Byron Lee

All Publications

• One Versus Two 3-Minute Cryoballoon Ablations Per Pulmonary Vein for Paroxysmal Atrial Fibrillation: The One Freeze Trial. Heart rhythm Lee, B. K., Guerra, P. G., Rho, R. W., Lee, S. Y., Dubuc, M., Dyrda, K., Fellows, C. L., Lee, R. J., Hue, T. F., Sarwary, S., Lin, F., Gerstenfeld, E. P. 2026

  View details for DOI 10.1016/j.hrthm.2026.07.007

  View details for PubMedID 42419469

• The Value of Functional Fascicular Block in Patients With Atrioventricular Re-Entrant Tachycardia. JACC. Clinical electrophysiology Higuchi, S., Gerstenfeld, E. P., Lee, A. C., Lee, B. K., Morin, D. P., Marcus, G. M., Hsia, H. H., Moss, J. D., Lee, R. J., Dewland, T. A., Vedantham, V., Tseng, Z. H., Patel, A. R., Tanel, R. E., Scheinman, M. M. 2025

  Abstract

  BACKGROUND: Changes in retrograde conduction time (Delta ventriculoatrial interval [DeltaVAI]) during functional complete bundle branch block (BBB) have been well established for localizing the accessory pathway (AP) in atrioventricular re-entrant tachycardia (AVRT).OBJECTIVES: This study investigated whether DeltaVAI during functional fascicular block (FB) provides more detailed AP localization and the significance of incomplete BBB in AVRT.METHODS: A total of 419 patients (age 22 ± 16 years; 39% male) with single non-decremental APs (left free wall, n = 207; septal, n = 159; and right free wall, n = 53) displaying functional FB (left anterior FB [LAFB], n = 66; left posterior FB [LPFB], n = 43) or BBB (right BBB, n = 183; left BBB, n = 136) during AVRT were studied. DeltaVAI was evaluated during FB, including isolated LAFB or LPFB, and during BBB, distinguishing between complete (QRS ≥120 milliseconds) or incomplete (QRS <120 milliseconds) BBB associated with each AP location.RESULTS: In patients with left free wall APs and right free wall APs, DeltaVAI increased with ipsilateral BBB. Complete BBB served to better distinguish AP location compared with incomplete BBB. LAFB produced DeltaVAI prolongation with left lateral and posterior-lateral APs, whereas no DeltaVAI was observed with left posterior and posterior-septal APs. In contrast, LPFB produced marked DeltaVAI lengthening with left posterior, posterior-lateral, and posterior-septal APs, whereas no DeltaVAI was observed with left lateral APs.CONCLUSIONS: In patients with AVRT, DeltaVAI during complete BBB enables more robust AP localization compared with incomplete BBB. Moreover, DeltaVAI during FB allows for AP localization along the mitral annulus, especially LAFB for left lateral APs and LPFB for posterior-septal and left posterior APs.

  View details for DOI 10.1016/j.jacep.2025.06.006

  View details for PubMedID 40772891

• Flecainide for the Treatment of Andersen-Tawil Syndrome. JACC. Clinical electrophysiology Mann, T. D., Yoruk, A., Neves, R. A., Bergman, A. T., Bos, M. J., van der Werf, C., Gollob, M. H., Roberts, J. D., Khan, H., Sanatani, S., Vedantham, V., Lee, B. K., Yesaulov, A., Krahn, A. D., Tadros, R., Wilde, A. A., Ackerman, M. J., Scheinman, M. M. 2025

  Abstract

  Andersen-Tawil syndrome type 1 (ATS1) is a rare arrhythmogenic disorder resulting from loss-of-function mutations in KCNJ2. Although the use of flecainide has been proposed to treat and prevent life-threatening arrhythmic events in ATS1, it has only been tested in small case series with limited follow-up. We performed a multicenter cohort study to determine the impact of flecainide on ATS.This study aimed to assess the efficacy and safety of flecainide in reducing ventricular arrhythmia and related symptoms in patients with ATS1.Clinical and genetic data from consecutive ATS1 patients from 9 centers were collected and entered into a database at UCSF Medical Center, San Francisco, California, USA, and pooled for analysis.The study included 31 ATS1 patients with a median age of 27 years (Q1-Q3: 24-38 years). The median follow-up time was 4.2 years (Q1-Q3: 1.6-9.7 years), and the median daily dose of flecainide was 150 mg (Q1-Q3: 100-200 mg). A positive exercise treadmill test was defined as any ventricular arrhythmia other than occasional single premature ventricular contractions, and was seen in 16 of 18 patients before treatment. This decreased to 5 of 18 patients with flecainide (OR: 0.13; P = 0.035). One episode of nonsustained ventricular tachycardia was observed on exercise treadmill test during flecainide treatment, compared with 6 observed during pretreatment. The ventricular arrhythmia score, defined as the most severe arrhythmia on Holter monitoring, improved in 66% of patients (mean improvement 0.62 ± 1.6 U; P = 0.005). Premature ventricular contraction burden decreased by 84.8% (71.5%-100%), from 22.3% at baseline to 3.8% with flecainide (P < 0.001). While on flecainide, symptomatic patients had a 77.7% chance of becoming symptom-free (95% CI: 56.2%-100%). Most patients (21/25, 84%) reported no side effects. One patient experienced a VT storm while treated with flecainide but tolerated a lower dose with a good response.These data demonstrate that flecainide treatment may be effective and well-tolerated in ATS1 patients. The occurrence of an arrhythmic storm in 1 patient underscores the potential for toxicity and mandates careful dose titration monitored by rest and exercise electrocardiogram for QRS widening.

  View details for DOI 10.1016/j.jacep.2025.03.020

  View details for PubMedID 40372332

• Loss of right ventricular capture: When it is not the lead's fault. HeartRhythm case reports Liu, A. Y., Marcus, G. M., Lee, B. K., Moss, J. D., Pellegrini, C. N. 2025; 11 (1): 2-7

  View details for DOI 10.1016/j.hrcr.2024.11.014

  View details for PubMedID 40330685

  View details for PubMedCentralID PMC12049706

• A Tale of 2 Troubling Tachycardias. JACC. Clinical electrophysiology Kataoka, S., Yogasundaram, H., Mann, T., Lee, B., Kumareswaran, R., Supple, G. E., Hsia, H. H., Callans, D. J., Scheinman, M. M. 2024

  View details for DOI 10.1016/j.jacep.2024.09.002

  View details for PubMedID 39480390

• Acute alcohol exposure and electrocardiographic changes: Finding from the HOLIDAY trial JOURNAL OF ELECTROCARDIOLOGY Ciuffo, L., Tung, M., Dukes, J. W., Vittinghoff, E., Moss, J. D., Lee, R. J., Lee, B. K., Tseng, Z. H., Vedantham, V., Olgin, J. E., Scheinman, M. M., Hsia, H., Ramchandani, V. A., Gerstenfeld, E. P., Marcus, G. M. 2024; 83: 26-29

  View details for DOI 10.1016/j.jelectrocard.2024.01.003

  View details for Web of Science ID 001175991000001

  View details for PubMedID 38295539

• Palpitations and Recurrent Syncope in a Young Woman CIRCULATION Lee, S., Lee, B. K. 2024; 149 (5): 402-405

  View details for DOI 10.1161/CIRCULATIONAHA.123.067865

  View details for Web of Science ID 001150598700006

  View details for PubMedID 38285741

• Comparison of non-laser and laser transvenous lead extraction: a systematic review and meta-analysis EUROPACE Akhtar, Z., Kontogiannis, C., Georgiopoulos, G., Starck, C. T., Leung, L. W. M., Lee, S. Y., Lee, B. K., Seshasai, S. R. K., Sohal, M., Gallagher, M. M. 2023; 25 (11)

  Abstract

  Transvenous lead extraction (TLE) is performed using non-laser and laser techniques with overall high efficacy and safety. Variation in outcomes between the two approaches does exist with limited comparative evidence in the literature. We sought to compare non-laser and laser TLE in a meta-analysis.We searched Medline, Embase, Scopus, ClinicalTrials.gov, and CENTRAL databases for TLE studies published between 1991 and 2021. From the included 68 studies, safety and efficacy data were carefully evaluated and extracted. Aggregated cases of outcomes were used to calculate odds ratio (OR), and pooled rates were synthesized from eligible studies to compare non-laser and laser techniques. Subgroup comparison of rotational tool and laser extraction was also performed. Non-laser in comparison with laser had lower procedural mortality (pooled rate 0% vs. 0.1%, P < 0.01), major complications (pooled rate 0.7% vs. 1.7%, P < 0.01), and superior vena cava (SVC) injury (pooled rate 0% vs. 0.5%, P < 0.001), with higher complete success (pooled rate 96.5% vs. 93.8%, P < 0.01). Non-laser comparatively to laser was more likely to achieve clinical [OR 2.16 (1.77-2.63), P < 0.01] and complete [OR 1.87 (1.69-2.08), P < 0.01] success, with a lower procedural mortality risk [OR 1.6 (1.02-2.5), P < 0.05]. In the subgroup analysis, rotational tool compared with laser achieved greater complete success (pooled rate 97.4% vs. 95%, P < 0.01) with lower SVC injury (pooled rate 0% vs. 0.7%, P < 0.01).Non-laser TLE is associated with a better safety and efficacy profile when compared with laser methods. There is a greater risk of SVC injury associated with laser sheath extraction.

  View details for DOI 10.1093/europace/euad316

  View details for Web of Science ID 001102685200006

  View details for PubMedID 37882609

  View details for PubMedCentralID PMC10638006

• Efficacy and mortality of rotating sheaths versus laser sheaths for transvenous lead extraction: a meta-analysis. Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing Lee, S. Y., Allen, I. E., Diaz, C., Guo, X., Pellegrini, C., Beygui, R., Cardona-Guarache, R., Marcus, G. M., Lee, B. K. 2023; 66 (5): 1067-1075

  Abstract

  Rotating and laser sheaths are both routinely used in transvenous lead extraction (TLE) which can lead to catastrophic complications including death. The efficacy and risk of each approach are uncertain. To perform a meta-analysis to compare success and mortality rates associated with rotating and laser sheaths.We searched electronic academic databases for case series of consecutive patients and randomized controlled trials published 1998-2017 describing the use of rotating and laser sheaths for TLE. Among 48 studies identified, rotating sheaths included 1,094 patients with 1,955 leads in 14 studies, and laser sheaths included 7,775 patients with 12,339 leads in 34 studies. Patients receiving rotating sheaths were older (63 versus 60 years old) and were more often male (74% versus 72%); CRT-P/Ds were more commonly extracted using rotating sheaths (12% versus 7%), whereas ICDs were less common (37% versus 42%), p > 0.05 for all. Infection as an indication for lead extraction was higher in the rotating sheath group (59.8% versus 52.9%, p = 0.002). The mean time from initial lead implantation was 7.2 years for rotating sheaths and 6.3 years for laser sheaths (p > 0.05).Success rates for complete removal of transvenous leads were 95.1% in rotating sheaths and 93.4% in laser sheaths (p < 0.05). There was one death among 1,094 patients (0.09%) in rotating sheaths and 66 deaths among 7,775 patients (0.85%) in laser sheaths, translating to a 9.3-fold higher risk of death with laser sheaths (95% CI 1.3 to 66.9, p = 0.01).Laser sheaths were associated with lower complete lead removal rate and a 9.3-fold higher risk of death.

  View details for DOI 10.1007/s10840-021-01076-x

  View details for PubMedID 34839431

  View details for PubMedCentralID PMC10333355

• A Randomized Trial of High vs Standard Power Radiofrequency Ablation for Pulmonary Vein Isolation SHORT-AF JACC-CLINICAL ELECTROPHYSIOLOGY Lee, A. C., Voskoboinik, A., Cheung, C. C., Yogi, S., Tseng, Z. H., Moss, J. D., Dewland, T. A., Lee, B. K., Lee, R. J., Hsia, H. H., Marcus, G. M., Vedantham, V., Chieng, D., Kistler, P. M., Dillon, W., Vittinghoff, E., Gerstenfeld, E. P. 2023; 9 (7): 1038-1047

  Abstract

  High-power, short duration (HPSD) radiofrequency ablation (RFA) is a commonly used strategy for pulmonary vein isolation (PVI).This study sought to compare HPSD with standard power, standard duration (SPSD) RFA in patients undergoing PVI.Patients with paroxysmal or persistent (<1 year) atrial fibrillation (AF) were randomized to HPSD (50 W) or SPSD (25-30 W) RFA to achieve PVI. Outcomes assessed included time to achieve PVI (primary), left atrial dwell time, total procedure time, first-pass isolation, PV reconnection with adenosine, procedure complications including asymptomatic cerebral emboli (ACE), and freedom from atrial arrhythmias.Sixty patients (median age 66 years; 75% male) with paroxysmal (57%) or persistent (43%) AF were randomized to HPSD (n = 29) or SPSD (n = 31). Median time to achieve PVI was shorter with HPSD vs SPSD (87 minutes vs 126 minutes; P = 0.003), as was left atrial dwell time (157 minutes vs 180 minutes; P = 0.04). There were no differences in first-pass isolation (79% vs 76%; P = 0.65) or PV reconnection with adenosine (12% vs 20%; P = 0.26) between groups. At 12 months, recurrent atrial arrhythmias occurred less in the HPSD group compared with the SPSD group (n = 3 of 29 [10%] vs n = 11 of 31 [35%]; HR: 0.26; P = 0.027). There was a trend toward more ACE with HPSD RFA (40% HPSD vs 17% SPSD; P = 0.053).In patients undergoing AF ablation, HPSD compared with SPSD RFA results in shorter time to achieve PVI, greater freedom from AF at 12 months, and a trend toward increased ACE.

  View details for DOI 10.1016/j.jacep.2022.12.020

  View details for Web of Science ID 001059867100001

  View details for PubMedID 37495318

• Randomized Comparison of a Radiofrequency Wire Versus a Radiofrequency Needle System for Transseptal Puncture JACC-CLINICAL ELECTROPHYSIOLOGY Dewland, T. A., Gerstenfeld, E. P., Moss, J. D., Lee, A. C., Vedantham, V., Lee, R. J., Tseng, Z. H., Hsia, H. H., Lee, B. K., Wall, G. C., Chang, K. R., Yang, M. H., Marcus, G. M. 2023; 9 (5): 611-619

  Abstract

  Transseptal puncture is a necessary component of many electrophysiology and structural heart procedures. Improving this technique has broad ramifications for the overall efficiency and safety of these interventions. A new technology uses a specialized introducer wire to cross the septum with radiofrequency (RF) energy, eliminating the need for a transseptal needle and wire/needle exchanges.This study sought to compare the efficacy and safety of an RF needle versus RF wire approach for transseptal puncture.Individuals ≥18 years of age undergoing double transseptal puncture for atrial fibrillation or left atrial flutter ablation were randomized to a transseptal approach with either an RF needle or RF wire. The primary outcome was time to achieve first transseptal puncture. Secondary outcomes included second and combined transseptal puncture time, fluoroscopy time, number of equipment exchanges, and complications.A total of 75 participants were enrolled (36 RF needle, 39 RF wire). No crossovers occurred. Randomization to the RF wire resulted in a significant reduction in first transseptal time compared with the RF needle (median 9.2 [IQR: 5.7-11.2] minutes vs 6.9 [IQR: 5.2-8.4] minutes, P = 0.03). Second and combined transseptal times, and number of equipment exchanges, were also reduced with the RF wire. One participant in the RF needle group experienced transient atrioventricular block due to mechanical trauma from the sheath/dilator assembly. There were no complications in the RF wire group.The RF wire technique resulted in faster time to transseptal puncture and fewer equipment exchanges compared with an RF needle with no difference in complications.

  View details for DOI 10.1016/j.jacep.2022.10.017

  View details for Web of Science ID 001055363700001

  View details for PubMedID 36752451

• The Value of Programmed Ventricular Extrastimuli From the Right Ventricular Basal Septum During Supraventricular Tachycardia. JACC. Clinical electrophysiology Higuchi, S., Ito, H., Gerstenfeld, E. P., Lee, A. C., Lee, B. K., Marcus, G. M., Hsia, H. H., Moss, J. D., Lee, R. J., Dewland, T. A., Vedantham, V., Tseng, Z. H., Patel, A. R., Tanel, R. E., Badhwar, N., Pellegrini, C. N., Kawamura, M., Shoda, M., Hwang, C., Refaat, M. M., Scheinman, M. M. 2023; 9 (2): 219-228

  Abstract

  The difference between the right ventricular (RV) apical stimulus-atrial electrogram (SA) interval during resetting of supraventricular tachycardia (SVT) versus the ventriculoatrial (VA) interval during SVT (ΔSA-VAapex) is an established technique for discerning SVT mechanisms but is limited by a significant diagnostic overlap.This study hypothesized that the difference between the RV SA interval during resetting of SVTs versus the VA interval during SVTs (ΔSA-VA) would yield a more robust differentiation of atrioventricular nodal re-entrant tachycardia (AVNRT) from atrioventricular reciprocating tachycardia (AVRT) when using the RV basal septal stimulation (ΔSA-VAbase) as compared to the RV apical stimulation (ΔSA-VAapex). Moreover, it was predicted that the ΔSA-VAbase might distinguish septal from free wall accessory pathways (APs) effectively.In this prospective study, 105 patients with AVNRTs (age 48 ± 20 years, 44% male) and 130 with AVRTs (age 26 ± 18 years, 54% male) underwent programmed ventricular extrastimuli delivered from both the RV basal septum and RV apex. The ΔSA-VA values were compared between the 2 sites.The ΔSA-VAbase was shorter than the ΔSA-VAapex during AVRT (44 ± 30 ms vs 58 ± 29 ms; P < 0.001), and the opposite occurred during AVNRT (133 ± 31 ms vs 125 ± 25 ms; P = 0.03). A ΔSA-VAbase of ≧85 milliseconds had a sensitivity of 97% and specificity of 96% for identifying AVNRT. Furthermore, a ΔSA-VAbase of 45-85 milliseconds identified AVRT with left free wall APs (sensitivity 86%, specificity 95%), 20-45 milliseconds for posterior septal APs (sensitivity 72%, specificity 96%), and <20 milliseconds for right free wall or anterior/mid septal APs (sensitivity 86%, specificity 98%).The ΔSA-VAbase during programmed ventricular extrastimuli produced a robust differentiation between AVNRT and AVRT regardless of the AP location with ≧85 milliseconds as an excellent cutoff point. This straightforward technique further allowed localizing 4 general AP sites.

  View details for DOI 10.1016/j.jacep.2022.09.005

  View details for PubMedID 36858688

• Premature Atrial Contraction Location and Atrial Fibrillation Inducibility. Circulation. Arrhythmia and electrophysiology Howell, S. J., Dukes, J. W., Vittinghoff, E., Tang, J. J., Moss, J. D., Lee, R. J., Lee, B. K., Tseng, Z. H., Vedantham, V., Olgin, J. E., Scheinman, M. M., Hsia, H., Gerstenfeld, E. P., Marcus, G. M. 2023; 16 (2): e011623

  View details for DOI 10.1161/CIRCEP.122.011623

  View details for PubMedID 36688298

  View details for PubMedCentralID PMC9974680

• Risk Factors for Arrhythmic Death, Overall Mortality, and Ventricular Tachyarrhythmias Requiring Shock After Myocardial Infarction AMERICAN JOURNAL OF CARDIOLOGY Lai, M., Cheung, C. C., Olgin, J., Pletcher, M., Vittinghoff, E., Lin, F., Hue, T., Lee, B. K. 2023; 187: 9

  Abstract

  The VEST (Vest Prevention of Early Sudden Death Trial) showed a trend toward decreased sudden death and lower overall mortality with a wearable cardioverter-defibrillator (WCD) in the postmyocardial infarction (post-MI) period. However, it is unclear which patients should receive WCD therapy. We aimed to identify the risk factors for arrhythmic death, all-cause mortality, and ventricular tachyarrhythmias requiring appropriate shock to identify patients most likely to benefit from a WCD. The VEST trial included patients with acute MI with ejection fraction ≤35%. Using logistic regression, 7 risk factors were evaluated for association with arrhythmic death, all-cause mortality, and appropriate shock. Among 2,302 participants, 44 had arrhythmic death (1.9%) and 86 died of any cause (3.7%). Among 1,524 participants randomized to WCD, 20 experienced appropriate shock (1.3%) over 90 days. In the multivariable analyses, lower systolic blood pressure (SBP; odds ratio [OR] 1.64 per 10 mm Hg) and higher heart rate at discharge (OR 1.19 per 10 beats/min) were associated with arrhythmic death. Lower SBP (OR 1.37) and higher heart rate (OR 1.10) were associated with all-cause mortality. Higher heart rate (OR 1.20) was associated with appropriate shock. Patients with both SBP ≤100 and heart rate ≥100 were at increased odds of arrhythmic death (OR 4.82), all-cause mortality (OR 3.10), and appropriate shock (OR 6.13). In patients with acute MI and reduced ejection fraction, lower SBP and higher heart rate at discharge were strongly associated with arrhythmic death and all-cause mortality. In conclusion, these risk factors identify a select group at high risk of adverse events in a setting where WCD therapy is reasonable.

  View details for DOI 10.1016/j.amjcard.2022.10.009

  View details for Web of Science ID 000916876200005

  View details for PubMedID 36459743

• US hospital webpages on atrial fibrillation ablation: A potential source for misinformation. Journal of cardiovascular electrophysiology Rajyaguru, C., Sandhu, U., Hadjis, A., Dere, J., Panchal, S., Ja, A., Ong, N., Yu, S., Yu, J., Lee, S. Y., Lee, B. K. 2022; 33 (9): 1987-1991

  Abstract

  Atrial fibrillation (AF) ablation is performed worldwide. To attract patients, hospitals frequently have webpages that tout the success of the procedure. The information disseminated to the public via these webpages has not been systematically reviewed. Our objective was to assess accuracy of information delivered to the public on hospital websites in regard to atrial AF ablation.From July 2019 to January 2020, we performed a Google search for all US hospitals registered with Medicare to see if they had a webpage describing AF ablation. Resulting hospital webpages were abstracted for data on AF ablation success rates and risks. Success rates over 86%, the highest success rate in the medical literature, were deemed exaggerated.Among 4805 hospitals, 487 had webpages describing AF ablation and 33 discussed success rates of AF ablation. Twelve percentage reported exaggerated success rates, 3% referred to ablation as a cure, and 2.8% referred to ablation as a tool to eliminate AF. Less than 10% of webpages describing AF ablation noted the potential need for a second ablation to achieve the stated success rate and merely 16% mentioned risks of the procedure. One percentage of webpages directly suggested AF ablation could reduce risk of stroke while others indirectly suggested it by discussing cessation of anticoagulation. Two webpages mentioned reduced mortality.US hospital webpages rarely discuss AF ablation. When discussed, there were concerning unsubstantiated claims regarding mortality, stroke prevention, and need for medical therapy. This could lead to some patients undergoing AF ablation based on faulty understanding.

  View details for DOI 10.1111/jce.15606

  View details for PubMedID 35726747

• From Improving Survival to Cost Savings for the Health SystemdRemote Monitoring for All? CANADIAN JOURNAL OF CARDIOLOGY Cheung, C. C., Lee, B. K. 2022; 38 (6): 712-714

  View details for DOI 10.1016/j.cjca.2022.01.032

  View details for Web of Science ID 000841434200004

  View details for PubMedID 35150823

• A peculiar case of palpitations and syncope HEART RHYTHM Cheung, C. C., Scheinman, M., Lee, B. K. 2022; 19 (3): 505-507

  View details for DOI 10.1016/j.hrthm.2021.11.019

  View details for Web of Science ID 000784332300029

  View details for PubMedID 35227417

• Performance of a Convolutional Neural Network and Explainability Technique for 12-Lead Electrocardiogram Interpretation. JAMA cardiology Hughes, J. W., Olgin, J. E., Avram, R., Abreau, S. A., Sittler, T., Radia, K., Hsia, H., Walters, T., Lee, B., Gonzalez, J. E., Tison, G. H. 2021; 6 (11): 1285-1295

  Abstract

  Millions of clinicians rely daily on automated preliminary electrocardiogram (ECG) interpretation. Critical comparisons of machine learning-based automated analysis against clinically accepted standards of care are lacking.To use readily available 12-lead ECG data to train and apply an explainability technique to a convolutional neural network (CNN) that achieves high performance against clinical standards of care.This cross-sectional study was conducted using data from January 1, 2003, to December 31, 2018. Data were obtained in a commonly available 12-lead ECG format from a single-center tertiary care institution. All patients aged 18 years or older who received ECGs at the University of California, San Francisco, were included, yielding a total of 365 009 patients. Data were analyzed from January 1, 2019, to March 2, 2021.A CNN was trained to predict the presence of 38 diagnostic classes in 5 categories from 12-lead ECG data. A CNN explainability technique called LIME (Linear Interpretable Model-Agnostic Explanations) was used to visualize ECG segments contributing to CNN diagnoses.Area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated for the CNN in the holdout test data set against cardiologist clinical diagnoses. For a second validation, 3 electrophysiologists provided consensus committee diagnoses against which the CNN, cardiologist clinical diagnosis, and MUSE (GE Healthcare) automated analysis performance was compared using the F1 score; AUC, sensitivity, and specificity were also calculated for the CNN against the consensus committee.A total of 992 748 ECGs from 365 009 adult patients (mean [SD] age, 56.2 [17.6] years; 183 600 women [50.3%]; and 175 277 White patients [48.0%]) were included in the analysis. In 91 440 test data set ECGs, the CNN demonstrated an AUC of at least 0.960 for 32 of 38 classes (84.2%). Against the consensus committee diagnoses, the CNN had higher frequency-weighted mean F1 scores than both cardiologists and MUSE in all 5 categories (CNN frequency-weighted F1 score for rhythm, 0.812; conduction, 0.729; chamber diagnosis, 0.598; infarct, 0.674; and other diagnosis, 0.875). For 32 of 38 classes (84.2%), the CNN had AUCs of at least 0.910 and demonstrated comparable F1 scores and higher sensitivity than cardiologists, except for atrial fibrillation (CNN F1 score, 0.847 vs cardiologist F1 score, 0.881), junctional rhythm (0.526 vs 0.727), premature ventricular complex (0.786 vs 0.800), and Wolff-Parkinson-White (0.800 vs 0.842). Compared with MUSE, the CNN had higher F1 scores for all classes except supraventricular tachycardia (CNN F1 score, 0.696 vs MUSE F1 score, 0.714). The LIME technique highlighted physiologically relevant ECG segments.The results of this cross-sectional study suggest that readily available ECG data can be used to train a CNN algorithm to achieve comparable performance to clinical cardiologists and exceed the performance of MUSE automated analysis for most diagnoses, with some exceptions. The LIME explainability technique applied to CNNs highlights physiologically relevant ECG segments that contribute to the CNN's diagnoses.

  View details for DOI 10.1001/jamacardio.2021.2746

  View details for PubMedID 34347007

  View details for PubMedCentralID PMC8340011

• Safety of transvenous lead removal in adult congenital heart disease: a national perspective. Revista espanola de cardiologia (English ed.) Guo, X., Hayward, R. M., Vittinghoff, E., Lee, S. Y., Harris, I. S., Pletcher, M. J., Lee, B. K. 2021; 74 (11): 943-952

  Abstract

  Data are scarce on outcomes of transvenous lead removal (TLR) in adult congenital heart disease (CHD). We evaluated the safety of the TLR procedure in adult CHD patients from a 10-year national database.We used the Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify TLR procedures in adult patients with and without CHD from 2005 to 2014. Outcomes included in-hospital mortality and complications.Of 132 068 adult patients undergoing TLR, 1939 had simple CHD, 657 had complex CHD, and 626 had unclassified CHD. The number of TLR procedures in adult CHD slightly increased from 236 in 2005 to 445 in 2014, with fluctuations over the study period. The overall rate of any complications in the TLR procedure was 16.6% in patients with CHD vs 10.1% in patients without CHD (P <.001). In a propensity score-matched cohort, CHD was associated with a higher risk of any complication after full adjustment vs patients without CHD (adjusted odd ratio, 1.49; 95% confidence interval, 1.11-1.99; P=.007). Simple and complex CHD were associated with 1.5- and 2.1-fold increased risks of any TLR-related complication, respectively. CHD was not associated with an increased risk of in-hospital mortality (adjusted odd ratio, 0.77; 95% confidence interval, 0.42-1.39; P=.386).Compared with patients without CHD, adult patients with simple and complex CHD undergoing TLR are more likely to have complications but show no increase in mortality.

  View details for DOI 10.1016/j.rec.2020.08.013

  View details for PubMedID 33127317

• Acute Consumption of Alcohol and Discrete Atrial Fibrillation Events ANNALS OF INTERNAL MEDICINE Marcus, G. M., Vittinghoff, E., Whitman, I. R., Joyce, S., Yang, V., Nah, G., Gerstenfeld, E. P., Moss, J. D., Lee, R. J., Lee, B. K., Tseng, Z. H., Vedantham, V., Olgin, J. E., Scheinman, M. M., Hsia, H., Gladstone, R., Fan, S., Lee, E., Fang, C., Ogomori, K., Fatch, R., Hahn, J. A. 2021; 174 (11): 1503-+

  Abstract

  Patients' self-reports suggest that acute alcohol consumption may trigger a discrete atrial fibrillation (AF) event.To objectively ascertain whether alcohol consumption heightens risk for an AF episode.A prospective, case-crossover analysis.Ambulatory persons in their natural environments.Consenting patients with paroxysmal AF.Participants were fitted with a continuous electrocardiogram (ECG) monitor and an ankle-worn transdermal ethanol sensor for 4 weeks. Real-time documentation of each alcoholic drink consumed was self-recorded using a button on the ECG recording device. Fingerstick blood tests for phosphatidylethanol (PEth) were used to corroborate ascertainments of drinking events.Of 100 participants (mean age, 64 years [SD, 15]; 79% male; 85% White), 56 had at least 1 episode of AF. Results of PEth testing correlated with the number of real-time recorded drinks and with events detected by the transdermal alcohol sensor. An AF episode was associated with 2-fold higher odds of 1 alcoholic drink (odds ratio [OR], 2.02 [95% CI, 1.38 to 3.17]) and greater than 3-fold higher odds of at least 2 drinks (OR, 3.58 [CI, 1.63 to 7.89]) in the preceding 4 hours. Episodes of AF were also associated with higher odds of peak blood alcohol concentration (OR, 1.38 [CI, 1.04 to 1.83] per 0.1% increase in blood alcohol concentration) and the total area under the curve of alcohol exposure (OR, 1.14 [CI, 1.06 to 1.22] per 4.7% increase in alcohol exposure) inferred from the transdermal ethanol sensor in the preceding 12 hours.Confounding by other time-varying exposures that may accompany alcohol consumption cannot be excluded, and the findings from the current study of patients with AF consuming alcohol may not apply to the general population.Individual AF episodes were associated with higher odds of recent alcohol consumption, providing objective evidence that a modifiable behavior may influence the probability that a discrete AF event will occur.National Institute on Alcohol Abuse and Alcoholism.

  View details for DOI 10.7326/M21-0228

  View details for Web of Science ID 000743694300015

  View details for PubMedID 34461028

• Incessant multiform ectopy in a young woman: What is the mechanism and treatment? HEART RHYTHM Rosenthal, D. G., Lee, B. K., Scheinman, M. M. 2021; 18 (9): 1615-1616

  View details for DOI 10.1016/j.hrthm.2021.05.027

  View details for Web of Science ID 000700405300021

  View details for PubMedID 34474745

• Predictors of long-term success after catheter ablation of premature ventricular complexes. Journal of cardiovascular electrophysiology Im, S. I., Voskoboinik, A., Lee, A., Higuchi, S., Moss, J. D., Hsia, H., Tseng, Z. H., Lee, R., Marcus, G. M., Vedantham, V., Scheinman, M., Lee, B., Park, K. M., Gerstenfeld, E. P. 2021; 32 (8): 2254-2261

  Abstract

  Some patients have late recurrence after acutely successful radiofrequency catheter ablation (RFCA) of premature ventricular complexes (PVCs). The aim of this study was to evaluate predictors of long-term success following acutely successful PVC RFCA.We identified consecutive patients at our institution with frequent PVCs undergoing RFCA and reviewed procedural data and medical records. Acute success was defined as elimination of targeted PVCs for at least 30-min after RFCA. Long-term success was defined as absence of targeted PVCs during all follow-up visits and PVC-burden <5% on follow-up monitoring.Among 241 patients (mean age 57 ± 15 years, 58% male), 161 (66.8%) had long-term success with median follow-up of 17.7 (IQR, 12.2-29.8) months. Unadjusted predictors of late PVC recurrence were increasing age, diabetes mellitus and alcohol use, while female-sex, shorter ablation-time, right ventricular PVC-origin, single PVC morphology, and earliest bipolar activation ≥24 ms pre-QRS were predictors of long-term success. In multivariate-analysis, female-sex, single-PVC morphology and earliest-onset of PVC ≥ 24 ms pre-QRS were independent predictors for long-term success. The positive-predictive value of earliest-bipolar onset of PVC ≥ 24 ms pre-QRS for long-term success was 0.77 (p < .001). Negative-predictive value of PVC < 15 ms pre-QRS for long-term success was 0.86 (p = .003), suggesting that RFCA when the bipolar electrogram preceded QRS by <15 ms was unlikely to result in long-term success.Female-sex, single-PVC morphology, and earliest-onset of bipolar electrogram ≥24 ms pre-QRS were multivariable predictors of long-term success in patients with PVCs undergoing RFCA. RFCA at sites with local onset <15 ms pre-QRS are unlikely to be successful.

  View details for DOI 10.1111/jce.15114

  View details for PubMedID 34041816

• Corrected QT Interval Is Associated With Stroke but Not Coronary Heart Disease: Insights From a General Chinese Population. Frontiers in cardiovascular medicine Guo, X., Li, Z., Zhou, Y., Yu, S., Yang, H., Sun, G., Zheng, L., Lee, B. K., Pletcher, M. J., Sun, Y. 2021; 8: 605774

  Abstract

  Background: Prolonged heart rate-corrected QT (QTc) interval has been associated with incident cardiovascular diseases (CVD) in general Western populations. However, this association is unclear in Asian population. We aim to estimate the association between QTc interval and incident CVD in a general Chinese population. Methods: We analyzed 8,867 participants age ≥35 years and free of CVD at baseline in the Northeast China Rural Cardiovascular Health Study. A resting 12-lead electrocardiogram was performed on all participants, and QTc interval computed using the Framingham formula. Cox proportional hazards models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for associations between QTc interval and incident stroke, coronary heart disease, and combined CVD events. Results: Over a median follow-up of 4.66 years, a total of 439 CVD events occurred (298 stroke cases and 152 CHD cases). After full adjustment, prolonged QTc defined by a sex-specific cutoff was associated with increased risk of developing stroke (HR: 1.82, 95% CI 1.20-2.75, P = 0.004) and combined CVD (HR: 1.52, 95% CI 1.05-2.19, P = 0.026). Spline analyses demonstrated no clear thresholds; when modeled as a linear relationship, each 10 ms increase of QTc interval was associated with an HR of 1.12 (95% CI 1.06-1.19, P < 0.001) for stroke and an HR of 1.10 (95% CI 1.05-1.15, P < 0.001) for combined CVD. Baseline QTc interval was not associated with incident CHD with either modeling strategy. Conclusions: Baseline QTc interval is associated with incident stroke and CVD in adults without prior CVD from a general Chinese population.

  View details for DOI 10.3389/fcvm.2021.605774

  View details for PubMedID 34368239

  View details for PubMedCentralID PMC8333696

• Performance and outcomes of transvenous rotational lead extraction: Results from a prospective, monitored, international clinical study. Heart rhythm O2 Sharma, S., Lee, B. K., Garg, A., Peyton, R., Schuler, B. T., Mason, P., Delnoy, P. P., Gallagher, M. M., Hariharan, R., Schaerf, R., Du, R., Serratore, N. D., Starck, C. T. 2021; 2 (2): 113-121

  Abstract

  Transvenous lead extraction (TLE) plays a critical role in managing patients with cardiovascular implantable electronic devices. Mechanical TLE tools, including rotational sheaths, are used to overcome fibrosis and calcification surrounding leads. Prospective clinical data are limited regarding the safety and effectiveness of use of mechanical TLE devices, especially rotational tools.To prospectively investigate the safety and effectiveness of mechanical TLE in real-world usage.Patients were enrolled at 10 sites in the United States and Europe to evaluate the use of mechanical TLE devices. Clinical success, complete procedural success, and complications were evaluated through follow-up (median, 29 days). Patient data were source verified and complications were adjudicated by an independent clinical events committee (CEC).Between October 2018 and January 2020, mechanical TLE tools, including rotational sheaths, were used to extract 460 leads with a median indwell time of 7.4 years from 230 patients (mean age 64.3 ± 14.4 years). Noninfectious indications for TLE were more common than infectious indications (61.5% vs 38.5%, respectively). The extracted leads included 305 pacemaker leads (66.3%) and 155 implantable cardioverter-defibrillator leads (33.7%), including 85 leads with passive fixation (18.5%). A bidirectional rotational sheath was needed for 368 leads (88.0%). Clinical success was obtained in 98.7% of procedures; complete procedural success was achieved for 96.3% of leads. CEC-adjudicated device-related major complications occurred in 6 of 230 (2.6%) procedures. No isolated superior vena cava injury or procedural death occurred.This prospective clinical study demonstrates that use of mechanical TLE tools, especially bidirectional rotational sheaths, are effective and safe.

  View details for DOI 10.1016/j.hroo.2021.02.005

  View details for PubMedID 34113913

  View details for PubMedCentralID PMC8183877

• Wearable cardioverter-defibrillators: A review of evidence and indications * , ** TRENDS IN CARDIOVASCULAR MEDICINE Cheung, C. C., Olgin, J. E., Lee, B. K. 2021; 31 (3): 196-201

  Abstract

  The wearable cardioverter-defibrillator (WCD) was first approved for clinical use in 2002, and is routinely used in select populations at high risk for sudden cardiac death. WCDs are frequently considered as a bridge to definitive therapy or in circumstances where insertion of conventional implantable cardioverter-defibrillators (ICD) is temporarily contraindicated. In this review, we summarize the literature on WCDs. From prospective trials to the first randomized controlled trial with WCD, there is a growing body of evidence that suggests that the WCD is safe and effective. In the first randomized controlled trial of the WCD (VEST Trial), there was no reduction in arrhythmia death but there was a reduction in all-cause mortality. We discuss the mortality impact, rate of inappropriate shocks, compliance, and potential quality of life implications with the WCD. Finally, we present the evidence for WCD use in select populations (e.g., post-myocardial infarction, device extraction), and the current guideline recommendations for WCD use.

  View details for DOI 10.1016/j.tcm.2020.03.002

  View details for Web of Science ID 000631796700011

  View details for PubMedID 32205034

• A Randomized, Double-Blind, Placebo-Controlled Trial of Intravenous Alcohol to Assess Changes in Atrial Electrophysiology. JACC. Clinical electrophysiology Marcus, G. M., Dukes, J. W., Vittinghoff, E. n., Nah, G. n., Badhwar, N. n., Moss, J. D., Lee, R. J., Lee, B. K., Tseng, Z. H., Walters, T. E., Vedantham, V. n., Gladstone, R. n., Fan, S. n., Lee, E. n., Fang, C. n., Ogomori, K. n., Hue, T. n., Olgin, J. E., Scheinman, M. M., Hsia, H. n., Ramchandani, V. A., Gerstenfeld, E. P. 2021

  Abstract

  This study sought to identify acute changes in human atrial electrophysiology during alcohol exposure.The mechanism by which a discrete episode of atrial fibrillation (AF) occurs remains unknown. Alcohol appears to increase the risk for AF, providing an opportunity to study electrophysiologic effects that may render the heart prone to arrhythmia.In this randomized, double-blinded, placebo-controlled trial, intravenous alcohol titrated to 0.08% blood alcohol concentration was compared with a volume and osmolarity-matched, masked, placebo in patients undergoing AF ablation procedures. Right, left, and pulmonary vein atrial effective refractory periods (AERPs) and conduction times were measured pre- and post-infusion. Isoproterenol infusions and burst atrial pacing were used to assess AF inducibility.Of 100 participants (50 in each group), placebo recipients were more likely to be diabetic (22% vs 4%; p = 0.007) and to have undergone a prior AF ablation (36% vs. 22%; p = 0.005). Pulmonary vein AERPs decreased an average of 12 ms (95% confidence interval: 1 to 22 ms; p = 0.026) in the alcohol group, with no change in the placebo group (p = 0.98). Whereas no statistically significant differences in continuously assessed AERPs were observed, the proportion of AERP sites tested that decreased with alcohol (median: 0.5; interquartile range: 0.6, 0.6) was larger than with placebo (median: 0.4; interquartile range: 0.2, 0.6; p = 0.0043). No statistically significant differences in conduction times or in the proportion with inducible AF were observed.Acute exposure to alcohol reduces AERP, particularly in the pulmonary veins. These data demonstrate a direct mechanistic link between alcohol, a common lifestyle exposure, and immediate proarrhythmic effects in human atria. (How Alcohol Induces Atrial Tachyarrhythmias Study [HOLIDAY]; NCT01996943).

  View details for DOI 10.1016/j.jacep.2020.11.026

  View details for PubMedID 33516710

• Electrophysiologic approach to diagnosis and ablation of patients with permanent junctional reciprocating tachycardia associated with complex anatomy and/or physiology. Journal of cardiovascular electrophysiology Oesterle, A., Lee, A. C., Voskoboinik, A., Moss, J. D., Vedantham, V., Walters, T. E., Lee, B. K., Tseng, Z. H., Gerstenfeld, E. P., Scheinman, M. M. 2020; 31 (12): 3232-3242

  Abstract

  Permanent junctional reciprocating tachycardia (PJRT) is a rare supraventricular tachycardia (SVT), typically involving a single decremental posteroseptal accessory pathway (AP).Four patients with long RP SVT underwent electrophysiology (EP) study and ablation. The cases were reviewed.Case 1 recurred despite 3 prior ablations at the site of earliest retrograde atrial activation during orthodromic reciprocating tachycardia (ORT). Mapping during a repeat EP study demonstrated a prepotential in the coronary sinus (CS). Ablation over the earliest atrial activation in the CS resulted in dissociation of the potential from the atrium during sinus rhythm. The potential was traced back to the CS os and ablated. Case 2 underwent successful ablation at 6 o'clock on the mitral annulus (MA). ORT recurred and successful ablation was performed at 1 o'clock on the MA. Case 3 had tachycardia with variation in both V-A and A-H intervals which precluded the use of usual maneuvers so we used simultaneous atrial and ventricular pacing and introduced a premature atrial contraction with a closely coupled premature ventricular contraction. Case 4 had had two prior atrial fibrillation ablations with continued SVT over a decremental atrioventricular bypass tract that was successfully ablated at 5 o'clock on the tricuspid annulus. A second SVT consistent with a concealed nodoventricular pathway was successfully ablated at the right inferior extension of the AV nodal slow pathway.We describe challenging cases of PJRT by virtue of complex anatomy, diagnostic features, and multiple arrhythmia mechanisms.

  View details for DOI 10.1111/jce.14788

  View details for PubMedID 33107135

• The wearable cardioverter-defibrillator is needed for most high-risk patients. Heart rhythm O2 Lee, B. K. 2020; 1 (3): 227-229

  View details for DOI 10.1016/j.hroo.2020.07.001

  View details for PubMedID 34113875

  View details for PubMedCentralID PMC8183972

• Predictors of adverse outcome in patients with frequent premature ventricular complexes: The ABC-VT risk score HEART RHYTHM Voskoboinik, A., Hadjis, A., Alhede, C., Im, S., Park, H., Moss, J., Marcus, G. M., Hsia, H., Lee, B., Tseng, Z., Lee, R., Scheinman, M., Vedantham, V., Vittinghoff, E., Park, K., Gerstenfeld, E. P. 2020; 17 (7): 1066-1074

  Abstract

  No independently validated score currently exists for risk stratification of patients with frequent premature ventricular complexes (PVCs).The purpose of this study was to develop a risk score to predict adverse events in patients with frequent PVCs.We analyzed consecutive patients between 2012 and 2017 undergoing 14-day continuous monitoring with frequent PVCs (>5%) and concurrent echocardiography. We performed binary logistic regression to determine multivariate predictors of adverse left ventricular remodeling (left ventricular ejection fraction [LVEF] <45% or left ventricular end-diastolic volume index >75 mL/m2). A risk score was created using the log(odds ratio (OR)) of these predictors and validated prospectively to determine the risk of future adverse events in those with baseline LVEF >45%. An adverse event was defined as LVEF decline by 10%, heart failure hospitalization, or cardiovascular mortality. Two validation cohorts were used: follow-up from the original derivation cohort (cohort 1) and an independent Korean PVC registry (cohort 2).The derivation cohort comprised 206 patients with a mean PVC burden of 11.6% ± 6.2% and considerable daily fluctuation (minimum burden 7.3% ± 6.2% vs maximum 17.9% ± 8.0%). Independent predictors of adverse remodeling were as follows: superiorly directed PVC axis (OR 2.7; 1 point), PVC burden 10%-20% (OR 3.5; 2 points) and >20% (OR 4.4; 3 points), PVC coupling interval >500 ms (OR 4.7; 4 points), nonsustained ventricular tachycardia (OR 5.3; 4 points), which form the ABC-VT risk score. This score predicted future adverse events in both validation cohorts: cohort 1, hazard ratio 1.43; 95% confidence interval 1.19-1.73; P < .001 and cohort 2, hazard ratio 1.22; 95% confidence interval 1.05-1.42; P = .01.The ABC-VT score is a simple tool that predicts adverse left ventricular remodeling and future clinical deterioration in patients with frequent PVCs.

  View details for DOI 10.1016/j.hrthm.2020.02.020

  View details for Web of Science ID 000544861000003

  View details for PubMedID 32109563

• Mortality during transvenous lead extraction: is there a difference between laser sheaths and rotating sheaths?-Authors' reply EUROPACE Lee, B. K., Diaz, C. L. 2020; 22 (6): 989-990

  View details for DOI 10.1093/europace/euaa054

  View details for Web of Science ID 000542050300026

  View details for PubMedID 32274509

• Impact of wearable cardioverter-defibrillator compliance on outcomes in the VEST trial: As-treated and per-protocol analyses. Journal of cardiovascular electrophysiology Olgin, J. E., Lee, B. K., Vittinghoff, E., Morin, D. P., Zweibel, S., Rashba, E., Chung, E. H., Borggrefe, M., Hulley, S., Lin, F., Hue, T. F., Pletcher, M. J. 2020; 31 (5): 1009-1018

  Abstract

  Vest Prevention of Early Sudden Death Trial did not demonstrate a significant reduction in arrhythmic death with the wearable cardioverter-defibrillator (WCD), but compliance with the device may have substantially affected the results. ThePletcher influence of WCD compliance on outcomes has not yet been fully evaluated.Using linear and pooled logistic models, we performed as-treated analyses omitting person-time in the hospital and adjusted for correlates of WCD compliance. To assess the impact of early stopping of WCD, we performed a per-protocol Kaplan-Meier analysis, censoring after the last day the WCD was worn. Interactions of potential effect modifiers with treatment assignment and WCD compliance on outcomes were investigated. Finally, we used linear models to identify predictors of WCD compliance.A per-protocol analysis demonstrated a significant reduction in total (P < .001) and arrhythmic (P = .001) mortality. Better WCD compliance was independently predicted by cardiac arrest during index myocardial infarction (MI), higher Cr, diabetes, prior heart failure, EF ≤ 25%, Polish enrolling center and number of WCD alarms, while worse compliance was predicted by being divorced, Asian race, higher body mass index, prior percutaneous coronary intervention, or any WCD shock. Neither excluding time in hospital from the as-treated analysis nor adjustment for factors affecting WCD compliance materially changed the results. No variable demonstrated a significant interaction in either the intention-to-treat or as-treated analysis.Robust sensitivity analyses of as-treated and per-protocol analyses suggest that the WCD is protective in compliant patients with ejection fraction less than or equal to 35% during the first 3 months post-MI.

  View details for DOI 10.1111/jce.14404

  View details for PubMedID 32083365

  View details for PubMedCentralID PMC9374026

• INTERACTION OF WIRELESS HEADPHONES, SMARTWATCHES, AND WIFI ROUTERS WITH ICDS Lee, B., An, N., Shi, E., Pokala, V., Chen, S. ELSEVIER SCIENCE INC. 2020: 499

  View details for Web of Science ID 000522979100488

• Wide Complex Tachycardia in a Woman in Her 30s With Electrolyte Derangements. JAMA cardiology Marano, P. J., Lee, A., Lee, B. K. 2020; 5 (2): 230-231

  View details for DOI 10.1001/jamacardio.2019.4838

  View details for PubMedID 31876899

• Reported mortality with rotating sheaths vs. laser sheaths for transvenous lead extraction. Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology Diaz, C. L., Guo, X., Whitman, I. R., Marcus, G. M., Pellegrini, C. N., Beygui, R. E., Lee, S. Y., Lee, B. K. 2019; 21 (11): 1703-1709

  Abstract

  Rotating sheaths and laser sheaths are commonly used for transvenous lead extraction. This study aims to compare observed mortality between both approaches.The Manufacturer and User Facility Device Experience database was searched from 2011 to 2016 to determine number of deaths associated with each sheath. An independent analytics firm provided estimates for number of cases done, allowing calculation of market share. A sensitivity analysis was performed to determine relative risk (RR) of mortality at the calculated market share (36% rotating/64% laser) and two others. Additional sensitivity analyses assumed underreporting of deaths associated with rotating sheaths. An estimated 50 545 extractions were performed. Thirteen deaths were associated with rotating sheaths compared to 167 with laser sheaths. Of these, 92% (rotating) and 95% (laser) were due to cardiovascular injury. At the calculated market share, the RR of death was 7.2 times greater with laser sheaths [95% confidence interval (CI) 4.1-12.7, P < 0.0001]. At market share estimates of 25% rotating/75% laser and 45% rotating/55% laser, the RR of death with laser sheaths was 4.3 (95% CI 2.4-7.5, P < 0.0001) and 10.5 times greater (95% CI 6.0-18.5, P < 0.0001), respectively. The RR of death remained significant when assuming deaths with rotating sheaths were underreported and when deaths using both sheaths were attributed to the rotating sheath.Lead extraction with laser sheaths appears to be associated with a higher risk of mortality compared to rotating sheaths. Further studies are warranted to confirm this finding.

  View details for DOI 10.1093/europace/euz238

  View details for PubMedID 31545350

• Impact of New Guidelines of Unscheduled and Scheduled Sedation for Cardiologists: JACC Council Perspectives. Journal of the American College of Cardiology Fisher, J. D., Welt, F. G., Villines, T. C., Truesdell, A. G., Young, M. N., Lakkireddy, D., Lee, B. K. 2019; 74 (11): 1505-1511

  Abstract

  Until 2019, guidelines for procedural sedation emphasized a detailed process most applicable for elective procedures scheduled well in advance. These guidelines provided by the American Society of Anesthesiologists were adopted by many specialties and institutions, and they have historically served the medical field well. However, cardiologists and other specialists often encounter urgent situations that demand unscheduled sedation. Physicians have been concerned about performing procedures in a fashion that "departs from the guidelines." In response, the American College of Emergency Physicians (ACEP) has developed a set of guidelines for patients requiring urgent unscheduled sedation. Many of the recommendations made within the novel ACEP guidelines are appropriate for cardiology, but there remain fundamental differences between trauma and other emergencies encountered in the emergency department and urgent cardiac procedures. This paper examines the differences between the American Society of Anesthesiologists and ACEP guidelines and provides some points to consider regarding best practices for cardiologists.

  View details for DOI 10.1016/j.jacc.2019.07.038

  View details for PubMedID 31514954

• Long-Term Corticosteroid-Sparing Immunosuppression for Cardiac Sarcoidosis. Journal of the American Heart Association Rosenthal, D. G., Parwani, P., Murray, T. O., Petek, B. J., Benn, B. S., De Marco, T., Gerstenfeld, E. P., Janmohamed, M., Klein, L., Lee, B. K., Moss, J. D., Scheinman, M. M., Hsia, H. H., Selby, V., Koth, L. L., Pampaloni, M. H., Zikherman, J., Vedantham, V. 2019; 8 (18): e010952

  Abstract

  Background Long-term corticosteroid therapy is the standard of care for treatment of cardiac sarcoidosis (CS). The efficacy of long-term corticosteroid-sparing immunosuppression in CS is unknown. The goal of this study was to assess the efficacy of methotrexate with or without adalimumab for long-term disease suppression in CS, and to assess recurrence and adverse event rates after immunosuppression discontinuation. Methods and Results Retrospective chart review identified treatment-naive CS patients at a single academic medical center who received corticosteroid-sparing maintenance therapy. Demographics, cardiac uptake of 18-fluorodeoxyglucose, and adverse cardiac events were compared before and during treatment and between those with persistent or interrupted immunosuppression. Twenty-eight CS patients were followed for a mean 4.1 (SD 1.5) years. Twenty-five patients received 4 to 8 weeks of high-dose prednisone (>30 mg/day), followed by taper and maintenance therapy with methotrexate±low-dose prednisone (low-dose prednisone, <10 mg/day). Adalimumab was added in 19 patients with persistently active CS or in those with intolerance to methotrexate. Methotrexate±low-dose prednisone resulted in initial reduction (88%) or elimination (60%) of 18-fluorodeoxyglucose uptake, and patients receiving adalimumab-containing regimens experienced improved (84%) or resolved (63%) 18-fluorodeoxyglucose uptake. Radiologic relapse occurred in 8 of 9 patients after immunosuppression cessation, 4 patients on methotrexate-containing regimens, and in no patients on adalimumab-containing regimens. Conclusions Corticosteroid-sparing regimens containing methotrexate with or without adalimumab is an effective maintenance therapy in patients after an initial response is confirmed. Disease recurrence in patients on and off immunosuppression support need for ongoing radiologic surveillance regardless of immunosuppression regimen.

  View details for DOI 10.1161/JAHA.118.010952

  View details for PubMedID 31538835

  View details for PubMedCentralID PMC6818011

• Variable Presentations and Ablation Sites for Manifest Nodoventricular/Nodofascicular Fibers. Circulation. Arrhythmia and electrophysiology Nazer, B., Walters, T. E., Dewland, T. A., Naniwadekar, A., Koruth, J. S., Najeeb Osman, M., Intini, A., Chen, M., Biermann, J., Steinfurt, J., Kalman, J. M., Tanel, R. E., Lee, B. K., Badhwar, N., Gerstenfeld, E. P., Scheinman, M. M. 2019; 12 (9): e007337

  Abstract

  BACKGROUND: Nodofascicular and nodoventricular (NFV) accessory pathways connect the atrioventricular node and the Purkinje system or ventricular myocardium, respectively. Concealed NFV pathways participate as the retrograde limb of supraventricular tachycardia (SVT). Manifest NFV pathways can comprise the anterograde limb of wide-complex SVT but are quite rare. The purpose of this report is to highlight the electrophysiological properties and sites of ablation for manifest NFV pathways.METHODS: Eight patients underwent electrophysiology studies for wide-complex tachycardia (3), for narrow-complex tachycardia (1), and preexcitation (4).RESULTS: NFV was an integral part of the SVT circuit in 3 patients. Cases 1 to 2 were wide-complex tachycardia because of manifest NFV SVT. Case 3 was a bidirectional NFV that conducted retrograde during concealed NFV SVT and anterograde causing preexcitation during atrial pacing. NFV was a bystander during atrioventricular node re-entrant tachycardia, atrial fibrillation, atrial flutter, and orthodromic atrioventricular re-entrant tachycardia in 4 cases and caused only preexcitation in 1. Successful NFV ablation was achieved empirically in the slow pathway region in 1 case. In 5 cases, the ventricular insertion was mapped to the slow pathway region (2 cases) or septal right ventricle (3 cases). The NFV was not mapped in cases 5 and 7 because of its bystander role. QRS morphology of preexcitation predicted the right ventricle insertion sites in 4 of the 5 cases in which it was mapped. During follow-up, 1 patient noted recurrent palpitations but no documented SVT.CONCLUSIONS: Manifest NFV may be critical for wide-complex tachycardia/manifest NFV SVT, act as the retrograde limb for narrow-complex tachycardia/concealed NFV SVT, or cause bystander preexcitation. Ablation should initially target the slow pathway region, with mapping of the right ventricle insertion site if slow pathway ablation is not successful. The QRS morphology of maximal preexcitation may be helpful in predicting successful right ventricle ablation site.

  View details for DOI 10.1161/CIRCEP.119.007337

  View details for PubMedID 31505948

• The wearable cardioverter-defibrillator vest: Indications and ongoing questions PROGRESS IN CARDIOVASCULAR DISEASES Sandhu, U., Rajyaguru, C., Cheung, C. C., Morin, D. P., Lee, B. K. 2019; 62 (3): 256-264

  Abstract

  Multiple clinical trials have demonstrated the efficacy of implantable cardioverter-defibrillators (ICDs) for the prevention of sudden cardiac death (SCD) among specific high-risk populations. However, it remains unclear how to optimally treat those patients who are at elevated risk of cardiac arrest but are not among the presently identified groups proven to benefit from an ICD, are unable to tolerate surgical device implantation, or refuse invasive therapies. The wearable cardioverter-defibrillator (WCD) is an alternative antiarrhythmic device that provides continuous cardiac monitoring and defibrillation capabilities through a noninvasive, electrode-based system. The WCD has been shown to be highly effective at restoration of sinus rhythm in patients with a ventricular tachyarrhythmia, and one randomized trial using the WCD in patients with recent myocardial infarction at elevated risk for arrhythmic death reported a decrease in overall mortality despite no SCD mortality benefit. The current clinical indications for WCD use are varied and continue to evolve as experience with this technology increases.

  View details for DOI 10.1016/j.pcad.2019.05.005

  View details for Web of Science ID 000474940300009

  View details for PubMedID 31077726

• Wearable Cardioverter-Defibrillator after Myocardial Infarction REPLY NEW ENGLAND JOURNAL OF MEDICINE Lee, B. K., Pletcher, M. J., Olgin, J. E. 2019; 380 (6): 600-601

  View details for Web of Science ID 000457854200019

• Wearable Cardioverter-Defibrillator after Myocardial Infarction. The New England journal of medicine Lee, B. K., Pletcher, M. J., Olgin, J. E. 2019; 380 (6): 600-601

  View details for DOI 10.1056/NEJMc1816889

  View details for PubMedID 30726697

• Surface ECG and intracardiac spectral measures predict atrial fibrillation recurrence after catheter ablation. Journal of cardiovascular electrophysiology Szilágyi, J., Walters, T. E., Marcus, G. M., Vedantham, V., Moss, J. D., Badhwar, N., Lee, B., Lee, R., Tseng, Z. H., Gerstenfeld, E. P. 2018; 29 (10): 1371-1378

  Abstract

  Outcome of patients undergoing catheter ablation of atrial fibrillation (AF) varies widely. We sought to investigate whether parameters derived from the spectral analysis of surface ECG and intracardiac AF electrograms can predict outcome in patients referred for pulmonary vein isolation (PVI).We performed spectral analysis on the surface ECG and intracardiac electrograms from patients referred for AF ablation. After filtering and QRST subtraction, we measured the dominant frequency (DF), regularity index (RI) and the organizational index (OI) of fibrillatory electrograms and determined their value for predicting AF recurrence after ablation. A subjective, blinded prediction based on the surface ECG was also performed.We analyzed data from 153 PVI procedures in 140 patients (67.1% with persistent or longstanding AF). In a multivariable model, DF in the right atrium (RA) and distal coronary sinus (CSd)-to-RA DF gradient predicted AF recurrence (OR, 3.52, P = 0.023 and OR, 0.2, P = 0.034, respectively). DF in RA and CSd to RA DF gradient had a good predictive value for PVI outcome (area under the curve [AUC] of 0.73, P = 0.007 and 0.74, P = 0.007, respectively). These performed better than the subjective predictions of experienced electrophysiologists ( P = 0.2).Higher RA DF, lower CSd to RA DF gradient predicted recurrence after AF ablation. These spectral measures suggest a more remodeled atrial substrate and may provide simple tools for risk stratification or predict the need for additional substrate modification in patients referred for AF ablation.

  View details for DOI 10.1111/jce.13699

  View details for PubMedID 30016007

• Wearable Cardioverter-Defibrillator after Myocardial Infarction NEW ENGLAND JOURNAL OF MEDICINE Olgin, J. E., Pletcher, M. J., Vittinghoff, E., Wranicz, J., Malik, R., Morin, D. P., Zweibel, S., Buxton, A. E., Elayi, C. S., Chung, E. H., Rashba, E., Borggrefe, M., Hue, T. F., Maguire, C., Lin, F., Simon, J. A., Hulley, S., Lee, B. K., VEST Investigators 2018; 379 (13): 1205–15

  Abstract

  Despite the high rate of sudden death after myocardial infarction among patients with a low ejection fraction, implantable cardioverter-defibrillators are contraindicated until 40 to 90 days after myocardial infarction. Whether a wearable cardioverter-defibrillator would reduce the incidence of sudden death during this high-risk period is unclear.We randomly assigned (in a 2:1 ratio) patients with acute myocardial infarction and an ejection fraction of 35% or less to receive a wearable cardioverter-defibrillator plus guideline-directed therapy (the device group) or to receive only guideline-directed therapy (the control group). The primary outcome was the composite of sudden death or death from ventricular tachyarrhythmia at 90 days (arrhythmic death). Secondary outcomes included death from any cause and nonarrhythmic death.Of 2302 participants, 1524 were randomly assigned to the device group and 778 to the control group. Participants in the device group wore the device for a median of 18.0 hours per day (interquartile range, 3.8 to 22.7). Arrhythmic death occurred in 1.6% of the participants in the device group and in 2.4% of those in the control group (relative risk, 0.67; 95% confidence interval [CI], 0.37 to 1.21; P=0.18). Death from any cause occurred in 3.1% of the participants in the device group and in 4.9% of those in the control group (relative risk, 0.64; 95% CI, 0.43 to 0.98; uncorrected P=0.04), and nonarrhythmic death in 1.4% and 2.2%, respectively (relative risk, 0.63; 95% CI, 0.33 to 1.19; uncorrected P=0.15). Of the 48 participants in the device group who died, 12 were wearing the device at the time of death. A total of 20 participants in the device group (1.3%) received an appropriate shock, and 9 (0.6%) received an inappropriate shock.Among patients with a recent myocardial infarction and an ejection fraction of 35% or less, the wearable cardioverter-defibrillator did not lead to a significantly lower rate of the primary outcome of arrhythmic death than control. (Funded by the National Institutes of Health and Zoll Medical; VEST ClinicalTrials.gov number, NCT01446965 .).

  View details for DOI 10.1056/NEJMoa1800781

  View details for Web of Science ID 000445835100005

  View details for PubMedID 30280654

  View details for PubMedCentralID PMC6276371

• Safety of Transvenous Lead Removal in Patients ≥70 Years of Age in the United States from 2005 to 2012. The American journal of cardiology Guo, X., Hayward, R. M., Vittinghoff, E., Liu, Y., Lee, S. Y., Pletcher, M. J., Lee, B. K. 2018; 122 (5): 799-805

  Abstract

  Cardiac devices are increasingly an element of treatment for the elderly, leading to more frequent transvenous lead removal (TLR) procedures in this population. Data on TLR in very elderly patients, especially nonagenarians, is scarce. We used Healthcare Cost and Utilization Project Nationwide Inpatient Sample to identify a total of 36,099 patients ≥70 years who underwent TLR from 2005 to 2012, with outcomes including in-hospital mortality and complications. The in-hospital mortality rate was significantly higher in nonagenarians without device infection (0.9% in age 70 to 79 vs 0.7% in age 80 to 89 vs 2.6% in age ≥90, p = 0.012), but overall complication rates were not different in age groups regardless of infection status and co-morbidity index (all p >0.05). Among patients with device infection, octogenarians, and nonagenarians were not associated with increased risk of in-hospital mortality relative to septuagenarians after controlling for all other confounders. However, in patients without device infection, logistic regression showed significantly higher mortality in patients age ≥90 years (odd ratio 4.22, 95% confidence interval 1.66 to 10.75, p = 0.003), but not in patients age 80 to 89 years (odd ratio 1.05, 95% confidence interval 0.48 to 2.30, p = 0.907), compared with patients age 70 to 79 years. In conclusion, in nonagenarians with infection, mortality is driven more by the patient's other conditions than by age. For patients without infection, however, nonagenarians experienced higher mortality than younger patients.

  View details for DOI 10.1016/j.amjcard.2018.05.014

  View details for PubMedID 30053999

• Crushing Heartbreak. Circulation Shah, M. M., Lee, B. K., Goldschlager, N. 2018; 138 (8): 838-842

  View details for DOI 10.1161/CIRCULATIONAHA.118.036372

  View details for PubMedID 30359119

• His Bundle Pacing. Journal of the American College of Cardiology Vijayaraman, P., Chung, M. K., Dandamudi, G., Upadhyay, G. A., Krishnan, K., Crossley, G., Bova Campbell, K., Lee, B. K., Refaat, M. M., Saksena, S., Fisher, J. D., Lakkireddy, D. 2018; 72 (8): 927-947

  Abstract

  Traditional right ventricular (RV) pacing for the management of bradyarrhythmias has been pursued successfully for decades, although there remains debate regarding optimal pacing site with respect to both hemodynamic and clinical outcomes. The deleterious effects of long-term RV apical pacing have been well recognized. This has generated interest in approaches providing more physiological stimulation, namely, His bundle pacing (HBP). This paper reviews the anatomy of the His bundle, early clinical observations, and current approaches to permanent HBP. By stimulating the His-Purkinje network, HBP engages electrical activation of both ventricles and may avoid marked dyssynchrony. Recent studies have also demonstrated the potential of HBP in patients with underlying left bundle branch block and cardiomyopathy. HBP holds promise as an attractive mode to achieve physiological pacing. Widespread adaptation of this technique is dependent on enhancements in technology, as well as further validation of efficacy in large randomized clinical trials.

  View details for DOI 10.1016/j.jacc.2018.06.017

  View details for PubMedID 30115232

• Effect of a single dose of i.v. ondansetron on QTc interval in emergency department patients AMERICAN JOURNAL OF HEALTH-SYSTEM PHARMACY Li, K., Vo, K., Lee, B. K., Addo, N., Coralic, Z. 2018; 75 (5): 276-282

  Abstract

  Results of a study to determine whether i.v. administration of a single dose of 4 mg of ondansetron was associated with QT interval prolongation in emergency department (ED) patients are reported.In a prospective observational study conducted at an urban academic medical center ED, a convenience sample of adult ED patients treated with ondansetron 4 mg i.v. were enrolled. A 12-lead electrocardiogram (ECG) was obtained immediately before and 5 minutes after ondansetron administration. Measurements of heart rate-corrected QT interval (QTc measurements) provided by ECG machines were evaluated. An electrophysiologist analyzed all ECGs for adverse electrical events and verified the accuracy of QTc values. The primary objective was to measure the QTc change from baseline after ondansetron administration. The secondary objective was to describe adverse electrical cardiac events. Interactions between ondansetron and patients' home medications or ED-provided medications were analyzed.Among patients included in the data analysis (n = 20), ondansetron administration was associated with a mean QTc increase of 16.2 msec (95% confidence interval, 4.2-28.2 msec; p = 0.01) and a median increase of 12 msec (interquartile range, 5.5-18.0 msec; p < 0.01). One patient had a significant cardiac event (pulseless electrical activity) that was likely unrelated to ondansetron use. The home medications of 9 patients (42.9%) were deemed to pose a risk of torsades de pointes, and 17 major QT-prolonging drug-drug interactions were identified.Significant QTc prolongation occurred in ED patients receiving a single 4-mg i.v. dose of ondansetron. None of the patients had an ondansetron-related cardiac adverse event.

  View details for DOI 10.2146/ajhp161070

  View details for Web of Science ID 000425958800006

  View details for PubMedID 29317399

• Trends in Hospitalizations for Cardiac Sarcoidosis in the United States, 2005-2011. Circulation journal : official journal of the Japanese Circulation Society Guo, X., Vittinghoff, E., Vedantham, V., Pletcher, M. J., Lee, B. K. 2017; 81 (11): 1739-1741

  Abstract

  Cardiac sarcoidosis (CS) is a life-threatening disease that is frequently under-diagnosed.We used a nationwide inpatient sample to identify CS patients from 2005 to 2011 in the USA. The annual admissions of CS increased from 1,108 in 2005 to 2,182 in 2011, representing a 2-fold rise over a short time. The proportions of CS patients with severe comorbidities, ventricular tachycardia, ventricular fibrillation and heart failure all increased from 2005 to 2011. However, the in-hospital mortality rate declined.An increasing trend of CS was observed. Cardiologists should notice that CS is not as rare as thought.

  View details for DOI 10.1253/circj.CJ-17-0701

  View details for PubMedID 28904267

• For cryoballoon ablation, time to effect is time well spent HEART RHYTHM Lee, B. K., Marcus, G. M. 2017; 14 (9): 1326-1327

  View details for DOI 10.1016/j.hrthm.2017.07.016

  View details for Web of Science ID 000408584300013

  View details for PubMedID 28713025

• Atrial fibrillation patients with isolated pulmonary veins: Is sinus rhythm achievable? Journal of cardiovascular electrophysiology Szilágyi, J., Marcus, G. M., Badhwar, N., Lee, B. K., Lee, R. J., Vedantham, V., Tseng, Z. H., Walters, T., Scheinman, M., Olgin, J., Gerstenfeld, E. P. 2017; 28 (7): 754-761

  Abstract

  The cornerstone of atrial fibrillation (AF) ablation is isolation of the pulmonary veins (PVs). Patients with recurrent AF undergoing repeat ablation usually have PV reconnection (PVr). The ablation strategy and outcome of patients undergoing repeat ablation who have persistent isolation of all PVs (PVi) at the time of repeat ablation is unknown.We studied consecutive patients with recurrent AF undergoing repeat ablation and compared patients with PVi to those with PVr. One hundred fifty-two patients underwent repeat ablation, and of these, 25 patients (16.4%) had PVi. Patients with PVi underwent ablation targeting any isoproterenol induced AF triggers, atrial substrate, or inducible atrial tachycardias or flutters. Patients with PVi compared to PVr were more likely to have a history of persistent AF (64% vs. 26%; P < 0.0001), obesity (BMI 30.4 vs. 28.2; P = 0.05), and prior use of contact force sensing catheters (28% vs. 0.8%, P < 0.0001). After a mean follow-up of 19 ± 15 months, 56% of PVi patients remained in sinus rhythm compared to 76.3% of PVr patients (P = 0.036). In a multivariable model, PVi patients and those with cardiomyopathy had a higher risk of recurrent atrial tachyarrhythmias (HR = 3.6 95%, CI 1.6-8.3, P = 0.002 and HR = 6.2, 95% CI 2.3-16.3, P < 0.0001, respectively).In patients who have all PVs isolated at the time of the redo AF ablation, a strategy of targeting non-PV AF triggers and inducible flutters can still lead to AF freedom in more than half of patients. Patients with PVr, however, have a better long-term outcome.

  View details for DOI 10.1111/jce.13230

  View details for PubMedID 28429499

• Primary Prevention of Sudden Cardiac Death Early Post-Myocardial Infarction Root Cause Analysis for Implantable Cardioverter-Defibrillator Failure and Currently Available Options CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Elayi, C. S., Charnigo, R. J., Heron, P. M., Lee, B. K., Olgin, J. E. 2017; 10 (6)

  View details for DOI 10.1161/CIRCEP.117.005194

  View details for Web of Science ID 000403880200011

  View details for PubMedID 28630173

• Outcomes of cardiac resynchronization therapy in patients with intermittent atrial fibrillation or atrial flutter in the COMPANION trial. Heart rhythm Kalscheur, M. M., Saxon, L. A., Lee, B. K., Steinberg, J. S., Mei, C., Buhr, K. A., DeMets, D. L., Bristow, M. R., Singh, S. N. 2017; 14 (6): 858-865

  Abstract

  Controlled clinical trial data are lacking for cardiac resynchronization therapy (CRT) outcomes in patients with advanced heart failure (HF) from reduced left ventricular ejection fraction (HFrEF) and intermittent atrial fibrillation or flutter (IAF/AFL).The purpose of this study was to describe CRT outcomes in patients with IAF/AFL and advanced HF.HF outcomes in patients in the COMPANION (Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure) trial with New York Heart Association class III or IV HFrEF, left ventricular ejection fraction ≤0.35, sinus rhythm at randomization, and no history of baseline arrhythmia were compared with those with a history of IAF/AFL.In those with no history of baseline arrhythmia (n = 887), compared with optimal pharmacological therapy (OPT) with no CRT, the CRT + OPT arms exhibited a significant reduction in the end points of death or any hospitalization (hazard ratio [HR] 0.73 [95% Confidence Interval (CI): 0.60 to 0.89]; P = .002) and death or HF hospitalization (HR 0.53 [95% CI: 0.41 to 0.68]; P < .001). In contrast, in the IAF/AFL subgroup (n = 293), CRT did not result in improved outcomes compared with OPT (death or any hospitalization: HR 1.16 [95% CI: 0.83 to 1.63]; P = .38; death or HF hospitalization: HR 0.97 [95% CI: 0.64 to 1.46]; P = .88). The interaction between history of AF/AFL and CRT was statistically significant for both outcomes (P < .05).In the COMPANION trial, patients with moderate to severe HFrEF and a history of IAF/AFL had no benefit from CRT.

  View details for DOI 10.1016/j.hrthm.2017.03.024

  View details for PubMedID 28323173

• Brain Emboli After Left Ventricular Endocardial Ablation CIRCULATION Whitman, I. R., Gladstone, R. A., Badhwar, N., Hsia, H. H., Lee, B. K., Josephson, S., Meisel, K. M., Dillon, W. P., Hess, C. P., Gerstenfeld, E. P., Marcus, G. M. 2017; 135 (9): 867-877

  Abstract

  Catheter ablation for ventricular tachycardia and premature ventricular complexes (PVCs) is common. Catheter ablation of atrial fibrillation is associated with a risk of cerebral emboli attributed to cardioversions and numerous ablation lesions in the low-flow left atrium, but cerebral embolic risk in ventricular ablation has not been evaluated.We enrolled 18 consecutive patients meeting study criteria scheduled for ventricular tachycardia or PVC ablation over a 9-month period. Patients undergoing left ventricular (LV) ablation were compared with a control group of those undergoing right ventricular ablation only. Patients were excluded if they had implantable cardioverter defibrillators or permanent pacemakers. Radiofrequency energy was used for ablation in all cases and heparin was administered with goal-activated clotting times of 300 to 400 seconds for all LV procedures. Pre- and postprocedural brain MRI was performed on each patient within a week of the ablation procedure. Embolic infarcts were defined as new foci of reduced diffusion and high signal intensity on fluid-attenuated inversion recovery brain MRI within a vascular distribution.The mean age was 58 years, half of the patients were men, half had a history of hypertension, and the majority had no known vascular disease or heart failure. LV ablation was performed in 12 patients (ventricular tachycardia, n=2; PVC, n=10) and right ventricular ablation was performed exclusively in 6 patients (ventricular tachycardia, n=1; PVC, n=5). Seven patients (58%) undergoing LV ablation experienced a total of 16 cerebral emboli, in comparison with zero patients undergoing right ventricular ablation (P=0.04). Seven of 11 patients (63%) undergoing a retrograde approach to the LV developed at least 1 new brain lesion.More than half of patients undergoing routine LV ablation procedures (predominately PVC ablations) experienced new brain emboli after the procedure. Future research is critical to understanding the long-term consequences of these lesions and to determining optimal strategies to avoid them.

  View details for DOI 10.1161/CIRCULATIONAHA.116.025546

  View details for Web of Science ID 000395549700014

  View details for PubMedID 28119381

• Comparison of remote magnetic navigation ablation and manual ablation of idiopathic ventricular arrhythmia after failed manual ablation. Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing Kawamura, M., Scheinman, M. M., Tseng, Z. H., Lee, B. K., Marcus, G. M., Badhwar, N. 2017; 48 (1): 35-42

  Abstract

  Catheter ablation for idiopathic ventricular arrhythmia (VA) is effective and safe, but efficacy is frequently limited due to an epicardial origin and difficult anatomy. The remote magnetic navigation (RMN) catheter has a flexible catheter design allowing access to difficult anatomy. We describe the efficacy of the RMN for ablation of idiopathic VA after failed manual ablation.Among 235 patients with idiopathic VA referred for catheter ablation, we identified 51 patients who were referred for repeat ablation after a failed manual ablation. We analyzed the clinical characteristics, including the successful ablation site and findings at electrophysiology study, in repeat procedures conducted using RMN as compared with manual ablation. Among these patients, 22 (43 %) underwent repeat ablation with the RMN and 29 (57 %) underwent repeat ablation with a manual ablation.Overall, successful ablation rate was significantly higher using RMN as compared with manual ablation (91 vs. 69 %, P = 0.02). Fluoroscopy time in the RMN was 17 ± 12 min as compared with 43 ± 18 min in the manual ablation (P = 0.009). Successful ablation rate in the posterior right ventricular outflow tract (RVOT) plus posterior-tricuspid annulus was higher with RMN as compared with manual ablation (92 vs. 50 %, P = 0.03). Neither groups exhibited any major complications.The RMN is more effective in selected patients with recurrent idiopathic VA after failed manual ablation and is associated with less fluoroscopy time. The RMN catheters have a flexible design enabling them to access otherwise difficult anatomy including the posterior tricuspid annulus and posterior RVOT.

  View details for DOI 10.1007/s10840-016-0158-x

  View details for PubMedID 27314679

• The QT Interval as a Noninvasive Marker of Atrial Refractoriness. Pacing and clinical electrophysiology : PACE Nguyen, K. T., Gladstone, R. A., Dukes, J. W., Nazer, B., Vittinghoff, E., Badhwar, N., Vedantham, V., Gerstenfeld, E. P., Lee, B. K., Lee, R. J., Tseng, Z. H., Olgin, J. E., Scheinman, M. M., Marcus, G. M. 2016; 39 (12): 1366-1372

  Abstract

  Atrial refractoriness may be an important determinant of atrial fibrillation (AF) risk, but its measurement is not clinically accessible. Because the QT interval predicts incident AF and the atrium and ventricle share repolarizing ion currents, we investigated the association between an individual's QT interval and atrial effective refractory period (AERP).In paroxysmal AF patients presenting for catheter ablation, the QT interval was measured from the surface 12-lead electrocardiogram. The AERP was defined as the longest S1-S2 coupling interval without atrial capture using a 600-ms drive cycle length.In 28 patients, there was a positive correlation between QTc and mean AERP. After multivariate adjustment, a 1-ms increase in QTc predicted a 0.70-ms increase in AERP.The QTc interval reflects the AERP, suggesting that the QTc interval may be used as a marker of atrial refractoriness relevant to assessing AF risk and mechanism-specific therapeutic strategies.

  View details for DOI 10.1111/pace.12962

  View details for PubMedID 27753113

  View details for PubMedCentralID PMC5195901

• The Wearable Cardioverter-Defibrillator Is It Now the Standard of Care? CIRCULATION Lee, B. K., Olgin, J. E. 2016; 134 (9): 644-646

  View details for DOI 10.1161/CIRCULATIONAHA.116.024287

  View details for Web of Science ID 000382288200009

  View details for PubMedID 27572878

• Predicting Persistent Left Ventricular Dysfunction Following Myocardial Infarction The PREDICTS Study JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Brooks, G. C., Lee, B. K., Rao, R., Lin, F., Morin, D. P., Zweibel, S. L., Buxton, A. E., Pletcher, M. J., Vittinghoff, E., Olgin, J. E., PREDICTS Investigators 2016; 67 (10): 1186-1196

  Abstract

  Persistent severe left ventricular (LV) systolic dysfunction after myocardial infarction (MI) is associated with increased mortality and is a class I indication for implantation of a cardioverter-defibrillator.This study developed models and assessed independent predictors of LV recovery to >35% and ≥50% after 90-day follow-up in patients presenting with acute MI and severe LV dysfunction.Our multicenter prospective observational study enrolled participants with ejection fraction (EF) of ≤35% at the time of MI (n = 231). Predictors for EF recovery to >35% and ≥50% were identified after multivariate modeling and validated in a separate cohort (n = 236).In the PREDICTS (PREDiction of ICd Treatment Study) study, 43% of patients had persistent EF ≤35%, 31% had an EF of 36% to 49%, and 26% had an EF ≥50%. The model that best predicted recovery of EF to >35% included EF at presentation, length of stay, prior MI, lateral wall motion abnormality at presentation, and peak troponin. The model that best predicted recovery of EF to ≥50% included EF at presentation, peak troponin, prior MI, and presentation with ventricular fibrillation or cardiac arrest. After predictors were transformed into point scores, the lowest point scores predicted a 9% and 4% probability of EF recovery to >35% and ≥50%, respectively, whereas profiles with the highest point scores predicted an 87% and 49% probability of EF recovery to >35% and ≥50%, respectively.In patients with severe systolic dysfunction following acute MI with an EF ≤35%, 57% had EF recovery to >35%. A model using clinical variables present at the time of MI can help predict EF recovery.

  View details for DOI 10.1016/j.jacc.2015.12.042

  View details for Web of Science ID 000371398700009

  View details for PubMedID 26965540

  View details for PubMedCentralID PMC4854198

• The Effect of Direct Current Stimulation versus T-Wave Shock on Defibrillation Threshold Testing. Pacing and clinical electrophysiology : PACE Ito, H., Kawamura, M., Badhwar, N., Vedantham, V., Tseng, Z. H., Lee, B. K., Lee, R. J., Marcus, G. M., Gerstenfeld, E. P., Scheinman, M. M. 2015; 38 (10): 1173-80

  Abstract

  There are several methods to induce ventricular fibrillation (VF) during defibrillation threshold (DFT) testing. Delivering a shock at a critical time during the T wave (T-shock) is the conventional approach, while delivering a constant direct current voltage (DC stim) from the implantable cardioverter defibrillator is an alternative method. Only a few reports compare VF induction methods. The purpose of this study was to evaluate the effects and safety of DC stim versus T-shock.We retrospectively investigated 414 consecutive patients undergoing DFT testing. We compared the two groups (DC stim and T-shock) with respect to clinical characteristics, electrocardiogram (ECG) changes, and complications.Ventricular arrhythmia, including ventricular tachycardia (VT) and VF, was induced by DC stim in 93 patients or T-shock in 321 patients. No more than three attempts were performed during one procedure. There was no significant difference in the baseline ECG, induced tachycardia cycle length (TCL), or complications between the two groups. However, the induced TCL was significantly shorter than the clinical TCL regardless of induction method (P = 0.001). Five patients suffered major complications (i.e., electromechanical dissociation or incessant VT). A history of atrial fibrillation was significantly greater in patients with major complications than the others (80% vs 24%, P = 0.004), and was an independent predictor on multivariate analysis.There is no significant difference in induced TCL or complications between the DC stim and T-shock. The induced TCL is significantly shorter than clinical TCL regardless of induction method.

  View details for DOI 10.1111/pace.12684

  View details for PubMedID 26137999

• Response to letter regarding article, "variable clinical features and ablation of manifest nodofascicular/ventricular pathways". Circulation. Arrhythmia and electrophysiology Hoffmayer, K. S., Lee, B. K., Vedantham, V., Bhimani, A. A., Cakulev, I. T., Mackall, J. A., Sahadevan, J., Rho, R. W., Scheinman, M. M. 2015; 8 (4): 995

  View details for DOI 10.1161/CIRCEP.115.003221

  View details for PubMedID 26286312

• Variable Clinical Features and Ablation of Manifest Nodofascicular/Ventricular Pathways CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Hoffmayer, K. S., Lee, B. K., Vedantham, V., Bhimani, A. A., Cakulev, I. T., Mackall, J. A., Sahadevan, J., Rho, R. W., Scheinman, M. M. 2015; 8 (1): 117-U185

  Abstract

  Manifest nodofascicular/ventricular (NFV) pathways are rare.From 2008 to 2013, 4 cases were identified with manifest NFV pathways from 3 centers. The clinical findings and ablation sites are reported. All 4 cases presented with a wide complex tachycardia but with different QRS morphologies. Case 1 showed a left bundle branch block/superior axis, case 2 showed a right bundle branch block/inferior axis, case 3 showed a left bundle branch block/inferior axis, and case 4 showed a narrow QRS tachycardia and a wide complex tachycardia with a left bundle branch block/inferior axis. Three of the 4 tachycardias had atrioventricular dissociation ruling out extranodal accessory pathways, including atriofascicular pathways. Programmed extrastimuli showed evidence of a decremental accessory pathway in 3 of the 4 cases. Coexisting tachycardia mechanisms were seen in 3 of the 4 cases (atrioventricular nodal reentry tachycardia [2] and atrioventricular reentrant tachycardia [1]). Ablation in the slow pathway region eliminated the NFV pathway in 3 (transient in 1) with the other responding to surgical closure of a large atrial septal defect. The NFV pathway was a critical part of the tachycardia circuit in 1 and proved to be a bystander in the other 3 cases.Manifest NFV pathways presented with variable QRS expression dependent on the ventricular insertion site and often coexisted with other tachycardia mechanisms (atrioventricular nodal reentry tachycardia and atrioventricular reentrant tachycardia). In most cases, the atrial insertion of the pathway was in or near the slow pathway region. The NFV pathways were either critical to the tachycardia circuit or served as bystanders.

  View details for DOI 10.1161/CIRCEP.114.001924

  View details for Web of Science ID 000349873000018

  View details for PubMedID 25472957

• Atrial fibrillation: antiarrhythmic therapy. Current problems in cardiology Psotka, M. A., Lee, B. K. 2014; 39 (10): 351-91

  Abstract

  Atrial fibrillation is the most common cardiac arrhythmia and is associated with significant morbidity, mortality, and economic cost. Although the benefit of anticoagulation has been well described, control of the underlying rhythm disturbance can be achieved in various ways. Numerous therapeutic options exist and continue to be developed; however, the single best strategy has not been elucidated, and rate or rhythm controlling strategies may both be undertaken. The selection of particular agents to successfully achieve these strategies takes into account patient preference and comorbidity, as well as the efficacy and side effect profiles of the possible medications. This review discusses the evidence behind the various agents typically used to treat atrial fibrillation as well as provides a framework on which to make clinical decisions while initiating and continuing therapy.

  View details for DOI 10.1016/j.cpcardiol.2014.07.004

  View details for PubMedID 25234389

• His overdrive pacing during supraventricular tachycardia: a novel maneuver for distinguishing atrioventricular nodal reentrant tachycardia from atrioventricular reciprocating tachycardia. Heart rhythm Singh, D. K., Viswanathan, M. N., Tanel, R. E., Lee, R. J., Lee, B. K., Marcus, G. M., Olgin, J. E., Han, F., Vedantham, V., Tseng, Z. H., Pellegrini, C., Kawamura, M., Gerstenfeld, E. P., Badhwar, N., Scheinman, M. 2014; 11 (8): 1327-35

  Abstract

  Because the His bundle is intrinsic to the circuit in orthodromic reciprocating tachycardia and remote from that of atrioventricular nodal reentrant tachycardia (AVNRT), pacing the His bundle during supraventricular tachycardia (SVT) may be useful to distinguish these arrhythmias.The purpose of this study was to test the hypothesis that His overdrive pacing (HOP) would affect SVT immediately for orthodromic reciprocating tachycardia and in a delayed manner for AVNRT.Once SVT was induced, HOP was performed by pacing the His bundle 10-30 ms faster than the SVT cycle length. The maneuver was determined to have entered the tachycardia circuit when a nonfused His-capture beat advanced or delayed the subsequent atrial electrogram by ≥10 ms or when the tachycardia was terminated. The number of beats required to enter each tachycardia with HOP was recorded.HOP was performed during 66 SVTs (26 atrioventricular reciprocating tachycardia [AVRT] and 40 AVNRT). Entry into the tachycardia within 1 beat had sensitivity of 92%, specificity of 92%, positive predictive value (PPV) of 89% and negative predictive value (NPV) of 95% to confirm the diagnosis of AVRT. A cutoff ≥3 beats to enter the circuit had sensitivity of 90%, specificity of 92%, PPV of 95% and NPV of 86% to confirm the diagnosis of AVNRT. HOP had sensitivity, specificity, PPV, and NPV of 100% for distinguishing septal AVRT from atypical AVNRT.HOP during SVT is a novel technique for distinguishing orthodromic reciprocating tachycardia from AVNRT. It can reliably distinguish between these arrhythmias with high sensitivity and specificity.

  View details for DOI 10.1016/j.hrthm.2014.04.038

  View details for PubMedID 24793458

• Coupling interval dispersion and body mass index are independent predictors of idiopathic premature ventricular complex-induced cardiomyopathy. Journal of cardiovascular electrophysiology Kawamura, M., Badhwar, N., Vedantham, V., Tseng, Z. H., Lee, B. K., Lee, R. J., Marcus, G. M., Olgin, J. E., Gerstenfeld, E. P., Scheinman, M. M. 2014; 25 (7): 756-62

  Abstract

  Patients with frequent premature ventricular complexes (PVCs) might be at risk for the developing or exacerbation of left ventricular (LV) dysfunction. However, some patients with a high-PVC burden do not develop cardiomyopathy, while other patients with low-PVC burden can develop cardiomyopathy. The purpose of this study was to evaluate the positive predictors of idiopathic PVCs-induced cardiomyopathy.We investigated 214 patients undergoing successful ablation of PVCs who had no other causes of cardiomyopathy. We divided the study cohort into 2 groups: ejection fraction (EF) ≥ 50% (normal LV) and EF < 50% (LV dysfunction). We analyzed the clinical characteristics, including the electrocardiogram and findings at electrophysiology study. Among these patients, 51 (24%) had reduced LVEF and 163 (76%) had normal LV function. Patients with LV dysfunction had significantly longer coupling interval (CI) dispersion (maximum-CI-minimum-CI) and had significantly higher PVC burden compared to those with normal LV function (CI-dispersion: 115 ± 25 milliseconds vs. 94 ± 19 milliseconds; P < 0.001; PVC burden: 19% vs. 15%; P = 0.04). Furthermore, patients with LV dysfunction had significantly higher body mass index (BMI) compared to those with normal LV function (BMI > 30 kg/m(2) ; 37% vs. 13%; P = 0.001). Logistic regression analysis showed that CI-dispersion, PVC burden, and BMI (>30 kg/m(2) ) are independent predictors of PVC-induced cardiomyopathy.In addition to the PVC burden, the CI-dispersion and BMI are associated with PVC-induced cardiomyopathy.

  View details for DOI 10.1111/jce.12391

  View details for PubMedID 24612052

• Safety of new oral anticoagulants for patients undergoing atrial fibrillation ablation. Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing Stepanyan, G., Badhwar, N., Lee, R. J., Marcus, G. M., Lee, B. K., Tseng, Z. H., Vedantham, V., Olgin, J., Scheinman, M., Gerstenfeld, E. P. 2014; 40 (1): 33-8

  Abstract

  The new oral anticoagulants (NOAC), dabigatran and rivaroxaban, have been demonstrated to be at least equivalent to warfarin for preventing cardiac thromboembolism (TE) in patients with atrial fibrillation (AF). However, there is limited data regarding use around catheter ablation (CA) procedures.We evaluated the risk of bleeding and TE complications associated with NOAC use during AF ablation.Consecutive patients undergoing AF ablation between January 2011 and 6 September 2013 were grouped based on peri-procedural anticoagulation regimen: (1) uninterrupted warfarin with therapeutic INR (WARF), n = 114, (2) dabigatran, n = 89, or (3) rivaroxaban, n = 98. NOACs were held for 24 h (dabigatran) or 36 h (rivaroxaban) prior to the procedure. Heparin infusion was initiated 6 h post-procedure for the NOAC groups; NOACs were resumed the morning after the procedure. Antral PVI was performed with activated clotting time (ACT) maintained >300 s. TE or bleeding complications during ablation and through 30 days were compared.Three hundred and one patients underwent ablation for paroxysmal (71%) or persistent (29%) AF. International Normalization Ratio (INR) for the WARF group was 2.0 ± 0.5. Baseline characteristics were similar among the groups. There were two TE events (asymptomatic cerebral emboli and TIA), and there were 17 bleeding events (large hematoma n = 4; pericardial effusion n = 6; persistent hematuria n = 1; pseudoaneurism/AV fistula n = 6). Of the six pericardial effusions, three required drainage. There was no significant difference in combined TE/bleeding risk among the groups (WARF vs. dabigatran vs. rivaroxaban; 6.2% vs. 6.7% vs. 6.0%; p = 0.82) CONCLUSIONS: In this group of AF patients undergoing CA, use of peri-procedure dabigatran or rivaroxaban compared to uninterrupted warfarin did not lead to an increase in bleeding or TE complications.

  View details for DOI 10.1007/s10840-014-9888-9

  View details for PubMedID 24643666

• Trainee inexperience is associated with longer procedure times but no increase in complications for cardiac device implantation. Heart rhythm Soleimani Rahbar, A., Hsu, J. C., Han, F. T., Nguyen, N., Kwon, M., Azadani, P. N., Marcus, G. M., Lee, B. K. 2013; 10 (12): 1755-8

  Abstract

  The "July phenomenon" describes poor patient outcomes in teaching hospitals at the beginning of a new academic year when trainees begin. Whether this phenomenon truly exists is unclear.The purpose of this study was to identify whether trainee and attending inexperience is associated with cardiac electrophysiologic procedural outcomes including total procedure time, fluoroscopy time, and complications.We retrospectively reviewed the available electronic records of 488 consecutive patients undergoing initial dual-chamber pacemaker (PM) or cardiac resynchronization therapy (CRT) device implantation performed at University of California, San Francisco from February 2004 through November 2011. We calculated physician's year of experience using the procedure date and the physician's job start date. Patients were stratified into two subgroups based on their device type. Procedural outcomes including procedure length, fluoroscopy time, and complications were retrieved from electronic databases.After multivariate analysis, fellow experience was associated with decreased procedure time (19% less procedure time/year of experience, 95% confidence interval [CI] 13%-25%, P <.001 in the PM subgroup; and 15% less procedure time/year of experience, 95% CI 7%-23%, P <.001 in the CRT subgroup). Fellow experience was associated with decreased fluoroscopy time in the CRT subgroup (19% less fluoroscopy time/experience years, 95% CI 5%-34%, P = .009). Neither fellow nor attending experience was associated with complications.Each year of fellow experience is associated with a decrease in cardiac device implantation procedure time and a decrease in fluoroscopy time during CRT implantation. No associations between fellow experience and in-hospital complications were observed.

  View details for DOI 10.1016/j.hrthm.2013.09.003

  View details for PubMedID 24016696

• Risk factors and prognosis for clot formation on cardiac device leads. Pacing and clinical electrophysiology : PACE Rahbar, A. S., Azadani, P. N., Thatipelli, S., Fleischmann, K. E., Nguyen, N., Lee, B. K. 2013; 36 (10): 1294-300

  Abstract

  Clot formation on cardiac device leads is poorly understood. We sought to determine how often clot is seen on device leads by transthoracic echo (TTE), identify risk factors, and to describe the natural history of this phenomenon.We reviewed 71,888 echocardiographic studies performed at the University of California, San Francisco from 2005 to 2011. We searched for cases where clot was found adhered to a device lead with no diagnosis of endocarditis. For every case, three age-matched controls with a device but no clot were selected from the echo database.We found 15 cases with clot adhered to a device lead among 1,086 patients with devices who had TTE (1.4%). In univariate analysis, females had more than four times greater odds of having a clot on their device lead and patients with a history of atrial fibrillation (AF) had an eight times greater odds. Percentage mode switch was also associated with clot formation. Only AF was still associated with clot formation after multivariate analysis. Follow-up data were available for nine of 15 patients. All nine patients had intensification of their anticoagulant/antiplatelet regimen following clot discovery. Complete resolution or shrinkage of clot was observed in eight of nine patients. The one case with no change was a patient who continued taking only aspirin (higher dose) after clot discovery. None of the nine patients had embolic phenomenon.Patients with AF are at higher risk for clot formation on device leads. After clot detection, treatment with anticoagulants usually results in resolution of the clot without embolic phenomenon.

  View details for DOI 10.1111/pace.12210

  View details for PubMedID 23844971

• Randomized trial of conventional transseptal needle versus radiofrequency energy needle puncture for left atrial access (the TRAVERSE-LA study). Journal of the American Heart Association Hsu, J. C., Badhwar, N., Gerstenfeld, E. P., Lee, R. J., Mandyam, M. C., Dewland, T. A., Imburgia, K. E., Hoffmayer, K. S., Vedantham, V., Lee, B. K., Tseng, Z. H., Scheinman, M. M., Olgin, J. E., Marcus, G. M. 2013; 2 (5): e000428

  Abstract

  Transseptal puncture is a critical step in achieving left atrial (LA) access for a variety of cardiac procedures. Although the mechanical Brockenbrough needle has historically been used for this procedure, a needle employing radiofrequency (RF) energy has more recently been approved for clinical use. We sought to investigate the comparative effectiveness of an RF versus conventional needle for transseptal LA access.In this prospective, single-blinded, controlled trial, 72 patients were randomized in a 1:1 fashion to an RF versus conventional (BRK-1) transseptal needle. In an intention-to-treat analysis, the primary outcome was time required for transseptal LA access. Secondary outcomes included failure of the assigned needle, visible plastic dilator shavings from needle introduction, and any procedural complication. The median transseptal puncture time was 68% shorter using the RF needle compared with the conventional needle (2.3 minutes [interquartile range {IQR}, 1.7 to 3.8 minutes] versus 7.3 minutes [IQR, 2.7 to 14.1 minutes], P = 0.005). Failure to achieve transseptal LA access with the assigned needle was less common using the RF versus conventional needle (0/36 [0%] versus 10/36 [27.8%], P < 0.001). Plastic shavings were grossly visible after needle advancement through the dilator and sheath in 0 (0%) RF needle cases and 12 (33.3%) conventional needle cases (P < 0.001). There were no differences in procedural complications (1/36 [2.8%] versus 1/36 [2.8%]).Use of an RF needle resulted in shorter time to transseptal LA access, less failure in achieving transseptal LA access, and fewer visible plastic shavings.

  View details for DOI 10.1161/JAHA.113.000428

  View details for PubMedID 24045120

  View details for PubMedCentralID PMC3835257

• Optimizing cardiac resynchronization therapy for congestive heart failure. Current problems in cardiology Duggirala, S., Lee, B. K. 2013; 38 (6): 215-37

  Abstract

  In patients with advanced systolic heart failure and mechanical dyssynchrony, cardiac resynchronization therapy (CRT) is an effective means of improving symptoms and reducing mortality. There are now several recognized approaches to optimize CRT. Imaging modalities can assist with identifying the myocardium with the latest mechanical activation for targeted left ventricular lead implantation. Device programming can be tailored to maximize biventricular pacing, and thereby is its benefit. Cardiac imaging has shown that atrioventricular and interventricular intervals can be adjusted to further reduce dyssynchrony. We review these various approaches that maximize the benefit derived from CRT.

  View details for DOI 10.1016/j.cpcardiol.2013.03.003

  View details for PubMedID 23664171

• Asymptomatic Left Bundle Branch Block Predicts New-Onset Congestive Heart Failure and Death From Cardiovascular Diseases. Cardiology research Azadani, P. N., Soleimanirahbar, A., Marcus, G. M., Haight, T. J., Hollenberg, M., Olgin, J. E., Lee, B. K. 2012; 3 (6): 258-263

  Abstract

  Left bundle branch block (LBBB) has been proposed as a risk factor for cardiovascular morbidity and mortality. We sought to characterize the strength of these associations in a population without preexisting clinical heart disease.The association between LBBB and new-onset congestive heart failure (CHF) or death from cardiovascular diseases was examined in 1,688 participants enrolled in the SPPARCS study who were free of known CHF or previous myocardial infarction. SPPARCS is a community-based cohort study in residents of Sonoma, California that are > 55 years. Medical history and 12-lead ECGs were obtained every 2 years for up to 6 years of follow-up. LBBB at enrollment or year 2 was considered "baseline" and assessed as a predictor of CHF and cardiovascular death ascertained at years 4 and 6.The prevalence of LBBB at baseline was 2.5% (n = 42). During 6 years of follow-up, 70 (4.8%) people developed new CHF. Incidence of CHF was higher in patients with LBBB than in participants without LBBB. This association persisted after controlling for potential confounders (odds ratio (OR): 2.85; 95% confidence interval (CI): 1.01 - 8.02; P = 0.047). A higher mortality from cardiovascular diseases was also found in participants with LBBB after adjusting for potential confounders (OR: 2.35, 95%CI: 1.02 - 5.41; P = 0.044).LBBB in the absence of a clinically detectable heart disease is associated with new-onset CHF and death from cardiovascular diseases. Further study is warranted to determine if additional diagnostic testing or earlier treatment in patients with asymptomatic LBBB can decrease cardiovascular morbidity or mortality.

  View details for DOI 10.4021/cr214w

  View details for PubMedID 28352414

  View details for PubMedCentralID PMC5358299

• Long-term electrical survival analysis of Riata and Riata ST silicone leads: National Veterans Affairs experience. Heart rhythm Sung, R. K., Massie, B. M., Varosy, P. D., Moore, H., Rumsfeld, J., Lee, B. K., Keung, E. 2012; 9 (12): 1954-61

  Abstract

  A medical device advisory issued by St Jude Medical in November 2011 estimated 0.63% all-cause abrasion rate on their Riata and Riata ST silicone high-voltage lead families (Riata/ST), leading to Food and Drug Administration class I recall. We performed an independent comparative, long-term electrical survival analysis of Riata/ST and 3 other high-voltage lead families in a large national cohort of patients.To evaluate long-term electrical survival of Riata/ST leads relative to other commonly evaluated high-voltage leads.Failure rates of Riata/ST, Sprint Quattro Secure (Quattro), Sprint Fidelis (Fidelis), and Endotak Reliance G/SG (Endotak) leads from the Veterans Administration's National Cardiac Device Surveillance Center database, consisting of 24,145 patients with remote transmissions since 2003, were analyzed. Survival Probabilities were determined with Kaplan-Meier survival analysis and compared using the log-rank test.Of 1,403 Riata/ST, 6,091 Quattro, 5,073 Fidelis, and 2,401 Endotak leads identified, 5-year survival probability of Riata/ST leads (97.5%) was significantly lower than that of Quattro (99.3%) and Endotak (99.4%) leads (P <.0001) but higher than that of Fidelis leads (89.6%) (P <.0001). Riata ST leads showed a 5-year survival of 95.5% (95% confidence interval 92.4-97.4) compared to 98.4% (95% confidence interval 97.1-99.1) in Riata leads (P = .003).There is decreased survival probability of Riata/ST leads compared to other contemporary high-voltage leads, with decreased survival of Riata ST silicone compared to Riata lead series. Careful long-term follow-up should be maintained in patients with Riata/ST leads in order to prevent inappropriate shocks or failed device interventions. Our results were determined in advance of Food and Drug Administration class I recall, which suggested that large-scale remote monitoring may be an effective tool for continued implantable cardioverter-defibrillator system surveillance.

  View details for DOI 10.1016/j.hrthm.2012.08.006

  View details for PubMedID 22871583

• Alcohol and vagal tone as triggers for paroxysmal atrial fibrillation. The American journal of cardiology Mandyam, M. C., Vedantham, V., Scheinman, M. M., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Gerstenfeld, E. P., Olgin, J. E., Marcus, G. M. 2012; 110 (3): 364-8

  Abstract

  Alcohol and vagal activity may be important triggers for paroxysmal atrial fibrillation (PAF), but it remains unknown if these associations occur more often than would be expected by chance alone because of the lack of a comparator group in previous studies. We compared self-reported frequency of these triggers in patients with PAF to those with other supraventricular tachycardias (SVTs). Consecutive consenting patients presenting for electrophysiology procedures at a single university medical center underwent a structured interview regarding arrhythmia triggers. Two hundred twenty-three patients with a documented arrhythmia (133 with PAF and 90 with SVT) completed the survey. After multivariable adjustment, patients with PAF had a 4.42 greater odds (95% confidence interval [CI] 1.35 to 14.44) of reporting alcohol consumption (p = 0.014) and a 2.02 greater odds (95% CI 1.02 to 4.00) of reporting vagal activity (p = 0.044) as an arrhythmia trigger compared to patients with SVT. In patients with PAF, drinking primarily beer was associated with alcohol as a trigger (odds ratio [OR] 4.49, 95% CI 1.41 to 14.28, p = 0.011), whereas younger age (OR 0.68, 95% CI 0.49 to 0.95, p = 0.022) and a family history of AF (OR 5.73, 95% CI 1.21 to 27.23, p = 0.028) each were independently associated with having vagal activity provoke an episode. Patients with PAF and alcohol triggers were more likely to have vagal triggers (OR 10.32, 95% CI 1.05 to 101.42, p = 0.045). In conclusion, alcohol consumption and vagal activity elicit PAF significantly more often than SVT. Alcohol and vagal triggers often were found in the same patients with PAF, raising the possibility that alcohol may precipitate AF by vagal mechanisms.

  View details for DOI 10.1016/j.amjcard.2012.03.033

  View details for PubMedID 22521307

  View details for PubMedCentralID PMC3398200

• Predictors of fluoroscopy time and procedural failure during biventricular device implantation. The American journal of cardiology Hsu, J. C., Badhwar, N., Lee, B. K., Vedantham, V., Tseng, Z. H., Marcus, G. M. 2012; 110 (2): 240-5

  Abstract

  Biventricular device implantation with the insertion of a transvenous left ventricular (LV) lead can be challenging. The aim of this study was to identify predictors of procedural difficulty measured by fluoroscopy time and predictors of LV lead implantation failure. A single-center, retrospective study of 272 consecutive patients who underwent biventricular device implantation from 2004 to 2011 was conducted. Multivariate linear regression was used to assess predictors of fluoroscopy time and logistic regression to identify predictors of LV lead implant failure. The median fluoroscopy time was 36.1 minutes (interquartile range 24.2 to 51.6). After multivariate adjustment, independent predictors of longer fluoroscopy time included a right-sided approach (21.8 minutes longer, 95% confidence interval [CI] 6.8 to 36.9, p = 0.005), previous congenital heart disease surgery (64.6 minutes longer, 95% CI 30.2 to 99.0, p <0.001), and previous failed attempt (30.3 minutes longer, 95% CI 6.0 to 54.5, p = 0.015). Predictors of shorter fluoroscopy time included an LV lead upgrade (7.5 minutes shorter, 95% CI 0.6 to 14.4, p = 0.033), electrophysiology fellow experience (5.4 minutes shorter/year, 95% CI 0.1 to 10.7, p = 0.047), and attending physician experience (1.4 minutes shorter/year, 95% CI 0.01 to 2.9, p = 0.049). Failed implantation occurred in 8% of patients (22 of 272); inability to cannulate the coronary sinus and absent or atretic coronary sinus veins were the most common reasons (8 of 22 failed implants each). A previous failed attempt was the only significant predictor of LV lead implantation failure (odds ratio 33.5, 95% CI 3.2 to 352.6, p = 0.003). In conclusion, 6 patient and operator characteristics predicted LV lead implantation difficulty measured by fluoroscopy time. LV lead implantation failed in 8% of cases, predicted only by a previous failed attempt.

  View details for DOI 10.1016/j.amjcard.2012.03.015

  View details for PubMedID 22483384

  View details for PubMedCentralID PMC3383869

• Predictors of axillary vein location for vascular access during pacemaker and defibrillator lead implantation. Pacing and clinical electrophysiology : PACE Hsu, J. C., Friday, J., Lee, B. K., Azadani, P. N., Lee, R. J., Badhwar, N., Tseng, Z. H., Olgin, J. E., Marcus, G. M. 2011; 34 (12): 1585-92

  Abstract

  The axillary vein is a commonly used extrathoracic access site for cardiac rhythm device lead implantation. We sought to describe variation in axillary vein location and identify predictors of a more cranial or caudal radiographic location to facilitate blind venous cannulation.This was a single-center, retrospective study of patients undergoing lead implantation between 2006 and 2010. The cranial-caudal location of the axillary vein lateral and medial to the rib cage border was determined by reviewing peripheral contrast venograms. Multivariate linear regression was performed.Of 155 patients, the majority were men (62%) and White (53%). The most frequent position of the lateral and medial axillary vein was over the third rib (40%) and top of the third rib (15%), respectively. In multivariate analysis, whites had a more caudal location of both the lateral (0.56 rib spaces lower, 95% confidence interval [CI] 0.22-0.91, P = 0.002) and medial axillary vein (0.50 rib spaces lower, 95% CI 0.85-0.91, P = 0.019). Other independent predictors included an approximate 3-4% higher rib space location for every digit increase in body mass index (BMI) (P = 0.049 for the lateral location and P = 0.016 for the medial location) and an approximate half rib space higher location for males (P = 0.015 for the lateral location and P = 0.013 for the medial location).The most common radiographic position of the axillary vein was over the third rib. Whites have a more caudal axillary vein location while men and patients with higher BMI have a more cranial position of the axillary vein.

  View details for DOI 10.1111/j.1540-8159.2011.03191.x

  View details for PubMedID 21819433

• The TASER safety controversy. Expert review of medical devices Soleimanirahbar, A., Lee, B. K. 2011; 8 (6): 661-3

  View details for DOI 10.1586/erd.11.53

  View details for PubMedID 22029461

• Predictors of unusual ECG characteristics in cavotricuspid isthmus-dependent atrial flutter ablation. Pacing and clinical electrophysiology : PACE Hoffmayer, K. S., Yang, Y., Joseph, S., McCabe, J. M., Bhave, P., Hsu, J., Ng, R. K., Lee, B. K., Badhwar, N., Lee, R. J., Tseng, Z. H., Olgin, J. E., Narayan, S. M., Marcus, G. M., Scheinman, M. M. 2011; 34 (10): 1251-7

  Abstract

  An unusual 12-lead electrocardiographic pattern may be present in patients with cavotricuspid isthmus (CTI)-dependent flutter. Using baseline patient characteristics and echocardiography, we sought to study predictors of unusual electrocardiogram (ECG) characteristics in patients with CTI-dependent atrial flutter. This was a dual-center, retrospective cohort study of 147 patients undergoing electrophysiology study and ablation for CTI-dependent atrial flutter.Among this cohort, 23 patients (16%) had unusual 12-lead ECG characteristics. Using multivariate logistic regression, we found two clinical predictors for having an unusual ECG pattern. A clockwise (CW) pattern at time of electrophysiology study was the strongest predictor of an unusual ECG pattern (odds ratio 15.3, 95% confidence interval [CI] 4.0-59.4, P < 0.005). In addition, patients with decreased systolic function had a 3.5 greater odds (95% CI 1.1-11.5, P = 0.037) of having an unusual ECG pattern.Our data demonstrate that among patients suffering from CTI-dependent atrial flutter who are referred for ablation, 16% will have unusual ECG patterns. Patients with CW atrial activation and left ventricle dysfunction have greater odds of manifesting unusual patterns by surface electrocardiogram.

  View details for DOI 10.1111/j.1540-8159.2011.03137.x

  View details for PubMedID 21605144

  View details for PubMedCentralID PMC3395429

• Funding source and author affiliation in TASER research are strongly associated with a conclusion of device safety AMERICAN HEART JOURNAL Azadani, P. N., Tseng, Z. H., Ermakov, S., Marcus, G. M., Lee, B. K. 2011; 162 (3): 533-537

  View details for DOI 10.1016/j.ahj.2011.05.025

  View details for Web of Science ID 000294447400018

• Unraveling the Enigma of Bangungut: Is Sudden Unexplained Nocturnal Death Syndrome (SUNDS) in the Philippines a Disease Allelic to the Brugada Syndrome? Philippine journal of internal medicine Gaw, A. C., Lee, B., Gervacio-Domingo, G., Antzelevitch, C., Divinagracia, R., Jocano, F. 2011; 49 (3): 165-176

  Abstract

  BACKGROUND: Sudden unexplained nocturnal death syndrome (SUNDS) has been reported worldwide. SUNDS is endemic in Southeast Asia and is colloquially known as Bangungut in the Philippines, Lai Tai in Thailand, and Pokkuri in Japan. Although SUNDS in Thailand and Japan have been determined to be phenotypically, genetically and functionally identical to the Brugada syndrome, the relationship between Bangungut/SUNDS in the Philippines and the Brugada syndrome has not been clarified. This paper explores the concordance between Bangungut/SUNDS and the Brugada syndrome. METHODS: We summarized autopsy studies on Bangungut retrieved from PubMed since 1917 and current epidemiological data on Philippine SUNDS to clarify its diagnostic features. We also reviewed current hypotheses of the pathophysiological mechanism of the Brugada syndrome to explore its applicability to Bangungut/SUNDS. RESULTS: The use of the term Bangungut is confusing as it includes many diseases that may cause SUNDS. However, our review reveals a notable subset of Bangungut, identified as Bangungut/SUNDS with no gross cardiac pathology that conforms to the clinical picture of the folk-belief of Bangungut and of the Brugada syndrome, namely: predominance among male in the 20-40 age range; sudden death during sleep or at rest, usually following ingestion of a large meal at night; and victims were in apparent good health prior to their demise. Current pathophysiological mechanisms of Brugada syndrome seemed plausible explanations for a majority of this subset of Bangungut/SUNDS. CONCLUSION: Bangungut/SUNDS and the Brugada syndrome appear closely related. Pathophysiological mechanisms of the Brugada syndrome may explain the enigma of Bangungut/SUND. Whether Bangungut/SUNDS is phenotypically, genetically and functionally an allele of the Brugada syndrome remains inconclusive due to lack of research data. We therefore proposed a research agenda including genetic testing and pharmacological challenge of probands and their family members suspected of SUNDS to conclusively establish the relationship between these two syndromes.

  View details for PubMedID 22844180

  View details for PubMedCentralID PMC3404490

• Frequency of Atrial Flutter After Adult Lung Transplantation AMERICAN JOURNAL OF CARDIOLOGY Azadani, P. N., Kumar, U. N., Yang, Y., Scheinman, M. M., Hoopes, C. W., Marcus, G. M., Rifkin, C., Olgin, J. E., Lee, B. K. 2011; 107 (6): 922-926

  Abstract

  Lung transplantation, which involves an anastomosis of the graft to the native left atrium, may increase the risk of left-side atrial flutter (AFL). Our aim was to evaluate the incidence, predisposing conditions, and course of AFL after lung transplantation in adults. Two hundred sixty-nine consecutive patients who underwent lung transplantation were studied retrospectively. All patients received a preoperative echocardiogram and postoperative electrocardiographic monitoring. All 12-lead electrocardiograms were reviewed. Typical or atypical AFL was diagnosed by 2 independent reviewers based on accepted criteria. Predictors of AFL were investigated separately using univariate and multivariate logistic regression analyses. AFL occurred in 35 of 269 patients (13%) over a mean of 12 days after transplantation. All patients who developed AFL had no previous atrial arrhythmia. Of these 35 patients, 24 (68.6%) had atypical AFL by electrocardiographic criteria. In multivariate logistic regression analysis, patients with idiopathic pulmonary fibrosis (IPF) were 2.9 times more likely to have AFL than those patients with lung transplant without IPF (p = 0.009). Other independent risk factors for AFL were advanced age and preoperative left atrial enlargement. Only 3 of 35 patients (8.6%) with AFL had persistent atrial arrhythmia and needed electrophysiologic study and ablation. In conclusion, AFL is common soon after lung transplantation. Those with IPF, advanced age, or left atrial enlargement are at increased risk. In most cases, AFL is a self-limited arrhythmia that resolves spontaneously with no need for ablation.

  View details for DOI 10.1016/j.amjcard.2010.10.076

  View details for Web of Science ID 000288825300020

  View details for PubMedID 21247524

• Prospective observations in the clinical and electrophysiological characteristics of intra-isthmus reentry. Journal of cardiovascular electrophysiology Yang, Y., Varma, N., Badhwar, N., Tanel, R. E., Sundara, S., Lee, R. J., Lee, B. K., Tseng, Z. H., Marcus, G. M., Kim, A. M., Olgin, J. E., Scheinman, M. M. 2010; 21 (10): 1099-106

  Abstract

  Intra-isthmus reentry (IIR) is a circuit within the cavotricuspid isthmus (CTI). The purpose of this study is to prospectively define the electrogram and surface ECG characteristics of IIR, and its clinical implications.Fourteen patients underwent electrophysiological studies and were found to have IIR. Detailed electrogram mapping of the CTI was available in all, electroanatomic mapping (EAM) in 8 of 14 (57%) patients. In all, entrainment mapping during tachycardia proved reentry, and showed that the anteroinferior CTI was out of the circuit and the septal CTI was in the circuit in 12 of 14 patients, whereas in 2, the circuit was confined within the mid and/or anteroinferior CTI. Fractionated potentials (FPs) spanning 34-71% of the tachycardia cycle length were recorded within the CTI in all, and double potentials were inscribed in 10 of 14 (71%). Analysis of the tricuspid annulus electrograms showed spontaneous shifts from a counterclockwise (CCW) to clockwise or fusion patterns. Surface ECGs showed either typical CCW pattern (12 patients) or atypical patterns (3 patients). The EAMs showed a focal pattern in 3, a CCW pattern in 5. The successful ablation site always occurred at the area with maximal FP duration. Over the same period, 33 of 384 (9%) patients who underwent ablation for CTI-dependent flutter had prior successful CTI ablation, 7 of 33 (21%) were found to have IIR during the redo procedure.(1) Electrogram and ECG patterns of IIR frequently show atypical flutter. (2) IIR was successfully ablated in an area of the CTI associated with maximal duration of FPs. (3) IIR is a significant cause of "recurrent flutter" in patients with prior CTI ablation.

  View details for DOI 10.1111/j.1540-8167.2010.01778.x

  View details for PubMedID 20455984

• Approach to Cardiac Device Malfunction. Cardiac electrophysiology clinics Lee, B. K. 2010; 2 (2): 267

  Abstract

  Dealing with cardiac device malfunctions can be fun. Most of the time, the cause of the patient's new symptom can be discovered and alleviated. The clinician needs to approach the patient in a step-by-step manner. A careful history and brief physical examination before device interrogation is important. Since cardiac devices are now incredibly complex, it is crucial for clinicians to be comfortable with calling on the device company's representative or its technical services for help.

  View details for DOI 10.1016/j.ccep.2010.01.012

  View details for PubMedID 28770760

• The Path Less Taken. Cardiac electrophysiology clinics Bhave, P. D., Lee, B. K. 2010; 2 (2): 273-275

  Abstract

  This case report illustrates the importance of obtaining and carefully analyzing a paced ECG immediately after pacemaker implantation. Early recognition of a malpositioned lead in the left ventricle would allow correction before the lead becomes difficult to remove. Chest radiography and echocardiography are simple tests that can help confirm appropriate lead placement.

  View details for DOI 10.1016/j.ccep.2010.01.014

  View details for PubMedID 28770762

• Ventricular Tachycardia After Implantable Cardioverter-Defibrillator Placement. Cardiac electrophysiology clinics Nguyen, D. T., Tseng, Z. H., Lee, B. K., Badhwar, N. 2010; 2 (2): 277–80

  Abstract

  Although implantation of an endocardial implantable cardioverter defibrillator (ICD) is meant to protect against ventricular arrhythmias, in some cases it can be paradoxically pro-arrhythmic. Recognition of this device complication, while rare, is important because it is potentially reversible and can be treated by managing the device, in lieu of, or in addition to, antiarrhythmics and catheter ablation of ventricular tachycardia (VT). This case describes VT caused by right ventricular pacing after ICD implantation.

  View details for DOI 10.1016/j.ccep.2010.01.013

  View details for PubMedID 28770763

• Intracardiac and extracardiac markers of inflammation during atrial fibrillation HEART RHYTHM Marcus, G. M., Smith, L. M., Ordovas, K., Scheinman, M. M., Kim, A. M., Badhwar, N., Lee, R. J., Tseng, Z. H., Lee, B. K., Olgin, J. E. 2010; 7 (2): 149-154

  Abstract

  A decrease in inflammation after cure of atrial arrhythmias suggests that such arrhythmias are proinflammatory, and lower inflammatory marker levels in the coronary sinus suggest that atrial arrhythmias result in intracardiac appropriation of inflammatory cytokines.The purpose of this study was to investigate the effect of atrial fibrillation on inflammatory markers drawn from intracardiac and extracardiac chambers.We performed a case-control study of 167 AF patients and 207 controls. Blood from intracardiac and extracardiac sites was obtained from a subset of patients undergoing curative AF ablation (n = 46).No significant differences in C-reactive protein (CRP) or interleukin-6 (IL-6) levels were seen between patients with and those without a history of AF. Both levels were significantly higher when blood was drawn during AF than during sinus rhythm: median CRP 3.1 mg/dL (interquartile range [IQR] 1.0-6.0) versus 1.7 mg/dL (IQR 0.7-3.9, P = .0005); median IL-6 2.3 ng/mL (IQR 1.5-3.9) versus 1.5 ng/mL (IQR 0.7-2.5, P = .007). This finding persisted after adjusting for potential confounders. AF ablation patients in AF exhibited a positive median left atrial minus coronary sinus gradient CRP (0.3 mg/dL, IQR -0.03-1.1), whereas those in sinus rhythm had a negative median left atrial minus coronary sinus gradient CRP (-0.2, IQR -0.8-[-0.02], P = .01). Femoral artery minus femoral vein gradients in AF versus sinus rhythm did not show any differences.AF at the time of the blood draw, rather than a history of AF, was independently associated with inflammation. Differences in transcardiac gradients suggest that AF results in sequestration of inflammatory cytokines in the heart.

  View details for DOI 10.1016/j.hrthm.2009.10.004

  View details for Web of Science ID 000276189400001

  View details for PubMedID 20022819

  View details for PubMedCentralID PMC2900773

• Differences in accessory pathway location by sex and race. Heart rhythm Hsu, J. C., Tanel, R. E., Lee, B. K., Scheinman, M. M., Badhwar, N., Lee, R. J., Tseng, Z. H., Olgin, J. E., Marcus, G. M. 2010; 7 (1): 52-6

  Abstract

  The etiology of accessory pathway (AP) formation is generally unknown.The purpose of this study was to test the hypothesis that AP formation is genetically mediated by examining whether AP location differs by sex and/or race, using sex and race as proxies to distinguish genetically different individuals.This was a single-center, retrospective cohort study of 282 consecutive patients undergoing their first electrophysiology study that revealed at least one AP between 2004 and 2008. Sex and race were compared with AP location determined by invasive electrophysiology study.Eighty-nine (52%) males and 40 (36%) females had a left posterior AP (P = .006). Sixty-four (57%) females had a right annular AP, compared with 55 (32%) males (P <.001). After adjusting for age and race, females had 2.8-fold greater odds of having a right annular AP compared with males (95% confidence interval [CI] 1.70-4.65 greater odds; P <.001). While right anterior (free-wall) pathways were rare in all other races (12%), a significantly larger proportion of Asians (n = 10, 26%) had a right anterior AP (P = .017). After adjusting for sex and age, Asians had 3.8-fold greater odds of having a right anterior AP compared with other races (95% CI 1.5-9.4 greater odds; P = .004).Females more commonly had right annular APs, and Asians had right anterior APs substantially more frequently than other races. These findings suggest that the pathogenesis of AP formation may have a genetic component.

  View details for DOI 10.1016/j.hrthm.2009.09.023

  View details for PubMedID 19914144

  View details for PubMedCentralID PMC2818171

• Role of wearable and automatic external defibrillators in improving survival in patients at risk for sudden cardiac death. Current treatment options in cardiovascular medicine Lee, B. K., Olgin, J. E. 2009; 11 (5): 360-5

  Abstract

  Cardiac arrest is a vexing public health problem. Fortunately, implantable cardioverter-defibrillators (ICDs) have been proven to decrease overall mortality in several populations at high risk for cardiac arrest. However, it is still unclear how to treat patients who have an elevated risk of cardiac arrest but are not in one of the identified high-risk groups proven to benefit from an ICD. It also is uncertain how to manage high-risk patients who have an accepted indication for an ICD but are unable or unwilling to have an ICD. In these clinical situations, the wearable defibrillator and automatic external defibrillator are options that should be considered. Both devices have been shown in small series to be highly effective at restoring sinus rhythm in patients with a ventricular tachyarrhythmia. However, there is still a lack of large-scale trials proving that these devices should be employed routinely in specific high-risk patient populations.

  View details for PubMedID 19846033

• Test characteristics of neck fullness and witnessed neck pulsations in the diagnosis of typical AV nodal reentrant tachycardia. Clinical cardiology Sakhuja, R., Smith, L. M., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E., Marcus, G. M. 2009; 32 (8): E13-8

  Abstract

  Claims in the medical literature suggest that neck fullness and witnessed neck pulsations are useful in the diagnosis of typical AV nodal reentrant tachycardia (AVNRT).Neck fullness and witnessed neck pulsations have a high positive predictive value in the diagnosis of typical AVNRT.We performed a cross-sectional study of consecutive patients with palpitations presenting to a single electrophysiology (EP) laboratory over a 1 year period. Each patient underwent a standard questionnaire regarding neck fullness and/or witnessed neck pulsations during their palpitations. The reference standard for diagnosis was determined by electrocardiogram and invasive EP studies.Comparing typical AVNRT to atrial fibrillation (AF) or atrial flutter (AFL) patients, the proportions with neck fullness and witnessed neck pulsations did not significantly differ: in the best case scenario (using the upper end of the 95% confidence interval (CI), none of the positive or negative predictive values exceeded 79%. After restricting the population to those with supraventricular tachycardia (SVT) other than AF or AFL, neck fullness again exhibited poor test characteristics; however, witnessed neck pulsations exhibited a specificity of 97% (95% CI: 90%-100%) and a positive predictive value of 83% (95% CI: 52%-98%). After adjustment for potential confounders, SVT patients with witnessed neck pulsations had a seven-fold greater odds of having typical AVNRT, p = 0.029.Although neither neck fullness nor witnessed neck pulsations are useful in distinguishing typical AVNRT from AF or AFL, witnessed neck pulsations are specific for the presence of typical AVNRT among those with SVT.

  View details for DOI 10.1002/clc.20455

  View details for PubMedID 19479968

  View details for PubMedCentralID PMC3200305

• Influence of left ventricular lead location on outcomes in the COMPANION study. Journal of cardiovascular electrophysiology Saxon, L. A., Olshansky, B., Volosin, K., Steinberg, J. S., Lee, B. K., Tomassoni, G., Guarnieri, T., Rao, A., Yong, P., Galle, E., Leigh, J., Ecklund, F., Bristow, M. R. 2009; 20 (7): 764-8

  Abstract

  There are no randomized controlled trial data that evaluate mortality and hospitalization rates in cardiac resynchronization therapy (CRT) recipients based on left ventricular (LV) lead location. We analyzed the event-driven outcomes of mortality and hospitalization as well as functional outcomes including Functional Class, Quality-of-Life, and 6-minute walk distance in 1,520 patients enrolled in the COMPANION study of CRT versus optimal medical therapy.Over a mean follow-up after implantation of 16.2 months, patients randomized to CRT, regardless of lead location, experienced benefit compared with optimized pharmacologic therapy (OPT), with respect to all-cause mortality or heart failure hospitalization. All but a posterior location showed benefit with respect to the all-cause mortality or all-cause hospitalization outcome. Mortality benefit in CRT-D patients was indifferent to LV lead position. All functional outcomes including 6-minute walk distance, Quality-of-Life (QOL) and Functional Class improved with CRT, regardless of LV lead location.LV lead location was not a major determinant of multiple measures of response to CRT therapy in the COMPANION Trial. While acute data indicate that a left lateral LV lead location results in the most favorable hemodynamic response, these chronic data suggest that positioning an LV lead in an anterior rather than a lateral or posterior LV location has similar benefit.

  View details for DOI 10.1111/j.1540-8167.2009.01444.x

  View details for PubMedID 19298563

• Relation of Taser (electrical stun gun) deployment to increase in in-custody sudden deaths. The American journal of cardiology Lee, B. K., Vittinghoff, E., Whiteman, D., Park, M., Lau, L. L., Tseng, Z. H. 2009; 103 (6): 877-80

  Abstract

  Despite controversy concerning their safety, use of electrical stun guns (Tasers) by law enforcement agencies is increasing. We examined the effect of Taser deployment on rates of (1) in-custody sudden deaths in the absence of lethal force, (2) lethal force (firearm) deaths, and (3) officer injuries (OIs) requiring emergency room visits. Under the Public Records Act and the Freedom of Information Act, 126 police and sheriff departments from California cities were mailed surveys requesting rates of each of the outcomes of interest for each of the 5 years preceding Taser deployment through the 5 years after deployment. To control for population size and crime rates, we used total annual arrests per city as reported to the Department of Justice. Fifty cities provided predeployment and postdeployment data on in-custody sudden death, 21 cities reported firearm deaths, and 4 cities reported OIs. The rate of in-custody sudden death increased 6.4-fold (95% confidence interval 3.2-12.8, p = 0.006) and the rate of firearm death increased 2.3-fold (95% confidence interval 1.3-4.0, p = 0.003) in the in the first full year after Taser deployment compared with the average rate in the 5 years before deployment. In years 2 to 5 after deployment, rates of the 2 events decreased to predeployment levels. We observed no significant change in the rate of serious OIs after Taser deployment. In conclusion, although considered by some a safer alternative to firearms, Taser deployment was associated with a substantial increase in in-custody sudden deaths in the early deployment period, with no decrease in firearm deaths or serious OIs.

  View details for DOI 10.1016/j.amjcard.2008.11.046

  View details for PubMedID 19268749

• Rates and severity of perforation from implantable cardioverter-defibrillator leads: A 4-year study JOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY Turakhia, M., Prasad, M., Olgin, J., Badhwar, N., Tseng, Z. H., Lee, R., Marcus, G. M., Lee, B. K. 2009; 24 (1): 47-52

  Abstract

  Although recent case reports and one small single-year observational study report a substantially increased rate of perforation with the St. Jude Riata series defibrillator lead, these results have not been externally validated.From 2004 to 2007, 593 implantable cardioverter-defibrillator (ICD) implants were performed by six faculty and 13 fellows at four University of California, San Francisco, CA, USA and affiliate hospitals. An electronic medical records system was systematically searched to identify clinically significant cases of ICD lead dislodgment or perforation. Of 307 (56%) St. Jude leads (all Riata series 6.3- and 7.3-French leads), 188 (29%) Medtronic leads (including 99 Sprint Fidelis 6.6 French leads), and 98 (15%) Guidant/Boston Scientific leads, there were three perforations in 593 cases (0.51%). One perforation occurred with a Medtronic Sprint Fidelis 6949 lead (0.53%), and two with a St. Jude Riata 1581 lead (0.65%). There were no statistically significant differences in perforation or dislodgement rates between manufacturers or lead models (p = NS for all). In both cases of perforation with the St. Jude Riata leads, the lead tip perforated through the pericardium into the pleural space.In our 4-year series of ICD implants, perforation and dislodgement rates were low, similar across all lead makes and models, and well below published and accepted complication rates. Our findings contradict previously-reported higher rates of perforation with the Riata lead. Registry and product performance reports should also classify complications by severity and outcome to provide a more complete assessment of product safety.

  View details for DOI 10.1007/s10840-008-9308-0

  View details for Web of Science ID 000262987700008

  View details for PubMedID 18855128

• Impact of advanced age on survival in patients with implantable cardioverter defibrillators EUROPACE Pellegrini, C. N., Lee, K., Olgin, J. E., Turakhia, M. P., Tseng, Z. H., Lee, R., Badhwar, N., Lee, B., Varosy, P. D. 2008; 10 (11): 1296-1301

  Abstract

  Given the selectivity of clinical trial patients and meager representation of elderly in the major implantable cardioverter defibrillator (ICD) randomized trials (<25%), whether such data apply to elderly patients overall is unclear. The purpose of our study is to understand the influence of age on mortality after ICD implantation.We performed a retrospective cohort study of 502 consecutive patients receiving ICDs from 1993 to 2003 at a single university hospital. The primary predictor was patient age, categorized as <65, 65-75, and >75 years at ICD implantation. The primary outcome was time to death. Mean follow-up was 4 years. Median survival after ICD implantation was 5.3 years among subjects >75 years, less than half that of the youngest group. After adjusting for potential confounders, compared with subjects <65 years of age, patients >75 years [hazard ratio (HR), 4.7; 95% confidence interval (CI), 2.8-7.9; P < 0.001] and those 65-75 years (HR, 2.8; 95% CI, 1.7-4.8; P < 0.001) were at greater risk of death. Increased age was associated with higher total, cardiac, and non-cardiac mortality (all P

  View details for DOI 10.1093/europace/eun253

  View details for Web of Science ID 000260556300009

  View details for PubMedID 18818212

  View details for PubMedCentralID PMC2721725

• Impact of Remote Magnetic Catheter Navigation on Ablation Fluoroscopy and Procedure Time PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY Kim, A. M., Turakhia, M., Lu, J., Badhwar, N., Lee, B. K., Lee, R. J., Marcus, G. M., Tseng, Z. H., Scheinman, M., Olgin, J. E. 2008; 31 (11): 1399-1404

  Abstract

  Remote magnetic catheter navigation (RCN) is gaining acceptance in clinical cardiac electrophysiology, but details regarding how RCN affects procedure execution are not well characterized.From January 1, 2005, to November 30, 2007, 721 cases were retrospectively analyzed and compared. Of these, 127 used RCN and 594 used manual catheter navigation (MCN). Data including procedure time, fluoroscopy time, ablation catheter, procedural success, and complications were extracted from our procedure database and compared between RCN and MCN.RCN use significantly decreased fluoroscopy time for atrial fibrillation (AF) ablation (-29 minutes, P < 0.001), atrioventricular nodal reentrant tachycardia ablation (-14 minutes, P < 0.001), and atrioventricular reentrant tachycardia ablation (-18 minutes, P = 0.045). While RCN significantly increased mean procedure time for AF (+36 minutes, P = 0.003) and atypical atrial flutter cases (+116 minutes, P = 0.016), RCN AF procedure time diminished with increasing number of cases performed. Two cases of tamponade occurred during AF ablation using MCN (2.2%, 2 of 91 cases). No tamponade occurred during all 75 AF ablations with RCN.RCN can reduce fluoroscopy time and may reduce complications during catheter ablation. While it may increase total procedure duration, procedure times decrease with increasing operator experience. (PACE 2008; 31:1399-1404).

  View details for DOI 10.1111/j.1540-8159.2008.01202.x

  View details for Web of Science ID 000262203600005

  View details for PubMedID 18950296

• QT Dispersion Is Not associated with Sudden Cardiac Death or Mortality in Heart Transplant Recipients HEART SURGERY FORUM Marcus, G. M., Hoang, K. L., Hunt, S. A., Chun, S. H., Lee, B. K. 2008; 11 (5): E281-E284

  Abstract

  Sudden cardiac death (SCD) has been shown to be a significant cause of death after heart transplantation. QT dispersion (QTd) is associated with SCD in several high-risk populations. We hypothesized that QTd would predict mortality and SCD in heart transplantation patients.We examined the clinical charts and most recent electrocardiograms (ECGs) for patients who received heart transplants at Stanford University Medical Center during the period 1981-1995. QTd was measured with all 12 leads and the precordial leads. Analysis was performed by a single reader blinded to patient outcomes.A total of 346 patients who had undergone transplantation had available ECGs and known outcomes; 155 of these patients died, and 42 of these deaths were attributed to SCD. The 12-lead mean QTd was not significantly different between outcome groups: patients who survived had a 12-lead mean QTd of 58 +/- 29 milliseconds and those who died had a 12-lead mean QTd of 61 +/- 32 milliseconds (P = .57). Patients who died from SCD had a 12-lead mean QTd of 57 +/- 31 milliseconds (P = .40), and those who died of other causes had a 12-lead mean QTd of 59 +/- 34 milliseconds (P = .36 vs those who died of SCD). Similarly, the precordial-lead mean QTd did not differ significantly between the different outcome groups.We found no correlation between QTd and SCD or mortality in heart transplant recipients. Until additional studies prove a positive association, QTd should not be used as a prognostic marker in these patients.

  View details for DOI 10.1532/HSF98.20081023

  View details for Web of Science ID 000265130200005

  View details for PubMedID 18948241

• Protracted CRP elevation after atrial fibrillation ablation. Pacing and clinical electrophysiology : PACE McCabe, J. M., Smith, L. M., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E., Marcus, G. M. 2008; 31 (9): 1146-51

  Abstract

  Atrial fibrillation (AF) has been linked to an inflammatory process detected through various biomarkers, including C-Reactive Protein (CRP). Early recurrence of AF within the first 3 months after curative AF ablation is not felt to reflect success or failure of the procedure. We hypothesized that this early recurrence is due to an inflammatory response to the ablation itself. We therefore sought to evaluate levels of CRP after AF ablation.We prospectively enrolled subjects undergoing AF ablation. A control group of patients undergoing ablation for supraventricular tachycardia (SVT) was also enrolled. Each patient had CRP drawn on the day of the procedure (prior to ablation) and during their first follow-up (median 49 days, interquartile range [IQR] 37-93) and second follow-up (median 147 days, IQR 141-257) clinic visits. Patient interviews were performed and medical histories reviewed for evidence of recurrent AF prior to the first follow-up.CRP levels significantly increased from baseline to first follow-up in the AF ablation group (P = 0.0017). CRP did not significantly change after SVT ablation (P = 0.92). Seventeen (45%) of the AF subjects exhibited recurrence of AF prior to first follow-up. After adjusting for multiple potential confounders, AF ablation patients with recurrent AF prior to their first follow-up had a statistically significant greater odds of having an increase in CRP (OR 21, 95% CI 1.1-417, P = 0.045).AF ablation generates an inflammatory response that persists for several weeks. This inflammation may explain early recurrence of AF after curative ablation.

  View details for DOI 10.1111/j.1540-8159.2008.01155.x

  View details for PubMedID 18834466

  View details for PubMedCentralID PMC2596767

• Episodic ventricular pacing with intact atrioventricular nodal function in a DDDR device: What is the rhythm and how can it be prevented? HEART RHYTHM Pellegrini, C. N., Yeh, R. W., Olgin, J., Lee, B. K. 2008; 5 (6): 897-898

  View details for DOI 10.1016/j.hrthm.2008.02.031

  View details for Web of Science ID 000256609200025

  View details for PubMedID 18534376

• A first-degree family history in lone atrial fibrillation patients HEART RHYTHM Marcus, G. M., Smith, L. M., Vittinghoff, E., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E. 2008; 5 (6): 826-830

  Abstract

  Atrial fibrillation (AF) may be due to an inherited trait, particularly in lone AF patients. A family history of AF in lone AF patients has not previously been compared with a family history of patients with AF and established risk factors (non-lone AF).The purpose of this study was to compare the frequency of having a first-degree relative with AF in lone and non-lone AF patients.We performed a case-control study of consecutive subjects presenting to a single electrophysiology laboratory. A convenience sample of subjects with no known arrhythmias was also enrolled.Four hundred twenty-nine subjects were enrolled: 136 had AF (54 with lone AF), 84 had atrial flutter, 158 had other supraventricular arrhythmias, and 51 had no known arrhythmias. Significantly more subjects with AF reported a first-degree family history of AF compared with the remainder of the cohort (25% vs. 5%; P <.001). In multivariable analysis adjusting for potential confounders, AF patients had a 6-fold greater odds of having a family member with AF (95% confidence interval [CI] 2.93-12.7; P <.001). Lone AF patients had a first-degree family member with AF substantially more often than those with non-lone AF (41% vs. 14%; P <.001). After adjusting for potential confounders, lone AF patients remained significantly more likely than other AF patients to have a first-degree relative with AF (OR 7.2; 95% CI 2.1-24.7; P = .002).Lone AF patients have a first-degree family member with AF substantially more often than other AF patients. This suggests that an inherited trait may be particularly important in this subgroup of patients.

  View details for DOI 10.1016/j.hrthm.2008.02.016

  View details for Web of Science ID 000256609200010

  View details for PubMedID 18468961

  View details for PubMedCentralID PMC2474569

• Alcohol intake is significantly associated with atrial flutter in patients under 60 years of age and a shorter right atrial effective refractory period PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY Marcus, G. M., Smith, L. M., Whiteman, D., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E. 2008; 31 (3): 266-272

  View details for DOI 10.1111/j.1540-8159.2008.00985.x

  View details for Web of Science ID 000253634600002

• Alcohol intake is significantly associated with atrial flutter in patients under 60 years of age and a shorter right atrial effective refractory period. Pacing and clinical electrophysiology : PACE Marcus, G. M., Smith, L. M., Whiteman, D., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E. 2008; 31 (3): 266-72

  Abstract

  Although evidence suggests that alcohol is associated with atrial fibrillation (AF), the association between alcohol and atrial flutter (AFL) has not been examined. The mechanism connecting alcohol and atrial arrhythmias is unknown.Alcohol intake was determined in 195 consecutive patients with AF and AFL. Control subjects included patients with other supraventricular arrhythmias (n = 132) and healthy subjects (n = 54). Because of important competing risk factors for atrial arrhythmias in the elderly, stratification by age was performed. In a subset, atrial effective refractory periods (AERPs) were obtained from the high right atrium and proximal and distal coronary sinus.AF and AFL patients were significantly more likely to be daily alcohol drinkers (27% vs 14% of controls, P = 0.001). In multivariable analysis, AFL patients < or = 60 years of age were significantly more likely to be daily drinkers than to drink no alcohol compared to controls (odds ratio 17, 95% confidence interval 1.6-192.0, P = 0.019). Progressively more frequent alcohol intake was significantly associated with a progressively greater odds of AFL in patients < or = 60 years of age (P = 0.045). Neither AF subjects of any age nor AFL subjects > 60 years of age exhibited significant associations with alcohol after multivariable adjustment. Right AERPs shortened significantly with increasing amounts of alcohol intake (P = 0.025), whereas left AERPs were not associated with alcohol intake.Alcohol intake is positively associated with AFL in younger patients. The mechanism may be related to a shortening of the right AERP.

  View details for DOI 10.1111/j.1540-8159.2008.00985.x

  View details for PubMedID 18307620

• Markers of inflammation before and after curative ablation of atrial flutter HEART RHYTHM Marcus, G. M., Smith, L. M., Glidden, D. V., Wilson, E., McCabe, J. M., Whiteman, D., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Otigin, J. E. 2008; 5 (2): 215-221

  Abstract

  Atrial arrhythmias are associated with inflammation. The cause and effect of the association are unknown.The purpose of this study was to test the hypothesis that atrial tachyarrhythmias contribute to inflammation.We performed a prospective observational study wherein C-reactive protein (CRP) and interleukin-6 (IL-6) levels from the femoral vein and coronary sinus (CS) were compared before curative ablation for atrial flutter (AFL; n = 59) and paroxysmal supraventricular tachycardia (SVT; n = 110). Follow-up levels were obtained at 1 and 6 months.Peripheral levels of both biomarkers were significantly higher in the AFL group. After multivariate adjustment, only those in the AFL group who presented in AFL or atrial fibrillation (AF) had significantly elevated CRP levels (odds ratio 1.26; P = .033). Levels of each marker were similar in the CS and peripheral blood in the SVT group; in the AFL group, both CRP and IL-6 were significantly lower in the CS than in the periphery (P = .0076 and P = .0021, respectively). CRP was significantly lower a median of 47 days after AFL ablation (from a median of 6.28 mg/L to a median of 2.92 mg/L; P = .028) and remained reduced at second follow-up. IL-6 decreased across three time points after AFL ablation (P = .002). No reduction in inflammatory biomarkers was observed after SVT ablation.CRP and IL-6 levels are elevated in patients presenting in AFL. Given the lower CS values in these patients, their origin appears to be systemic rather than cardiac. Because these levels significantly fall after ablation of AFL, the atrial tachyarrhythmia appears to be the cause (not the effect) of the inflammation.

  View details for DOI 10.1016/j.hrthm.2007.10.007

  View details for Web of Science ID 000253239100008

  View details for PubMedID 18242542

  View details for PubMedCentralID PMC2247371

• Unusual atrial-paced tachycardia after pacemaker implantation: what is the mechanism? Heart rhythm Viswanathan, M. N., Tseng, Z. H., Goldschlager, N., Lee, B. K. 2007; 4 (6): 800-2

  View details for DOI 10.1016/j.hrthm.2007.02.003

  View details for PubMedID 17556209

• Inductionless or limited shock testing is possible in most patients with implantable cardioverter-defibrillators/cardiac resynchronization therapy defibrillators - Results of the multicenter ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation with Implantable Cardioverter-Defibrillator Implantations) CIRCULATION Day, J. D., Doshi, R. N., Belott, P., Birgersdotter-Green, U., Behboodikhah, M., Ott, P., Glatter, K. A., Tobias, S., Frumin, H., Lee, B. K., Merillat, J., Wiener, I., Wang, S., Grogin, H., Chun, S., Patrawalla, R., Crandall, B., Osborn, J. S., Weiss, J. P., Lappe, D. L., Neuman, S. 2007; 115 (18): 2382-2389

  Abstract

  Implantable cardioverter-defibrillators and cardiac resynchronization therapy defibrillators have relied on multiple ventricular fibrillation (VF) induction/defibrillation tests at implantation to ensure that the device can reliably sense, detect, and convert VF. The ASSURE Study (Arrhythmia Single Shock Defibrillation Threshold Testing Versus Upper Limit of Vulnerability: Risk Reduction Evaluation With Implantable Cardioverter-Defibrillator Implantations) is the first large, multicenter, prospective trial comparing vulnerability safety margin testing versus defibrillation safety margin testing with a single VF induction/defibrillation.A total of 426 patients receiving an implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator underwent vulnerability safety margin or defibrillation safety margin screening at 14 J in a randomized order. After this, patients underwent confirmatory testing, which required 2 VF conversions without failure at < or = 21 J. Patients who passed their first 14-J and confirmatory tests, irrespective of the results of their second 14-J test, had their devices programmed to a 21-J shock for ventricular tachycardia (VT) or VF > or = 200 bpm and were followed up for 1 year. Of 420 patients who underwent 14-J vulnerability safety margin screening, 322 (76.7%) passed. Of these, 317 (98.4%) also passed 21-J confirmatory tests. Of 416 patients who underwent 14-J defibrillation safety margin screening, 343 (82.5%) passed, and 338 (98.5%) also passed 21-J confirmatory tests. Most clinical VT/VF episodes (32 of 37, or 86%) were terminated by the first shock, with no difference in first shock success. In all observed cases in which the first shock was unsuccessful, subsequent shocks terminated VT/VF without complication.Although spontaneous episodes of fast VT/VF were limited, there was no difference in the odds of first shock efficacy between groups. Screening with vulnerability safety margin or defibrillation safety margin may allow for inductionless or limited shock testing in most patients.

  View details for DOI 10.1161/CIRCULATIONAHA.106.663112

  View details for Web of Science ID 000246278000005

  View details for PubMedID 17470697

• Impact of renal function on survival in patients with implantable cardioverter-defibrillators PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY Turakhia, M. P., Varosy, P. D., Lee, K., Tseng, Z. H., Lee, R., Badhwar, N., Scheinman, M., Lee, B. K., Olgin, J. E. 2007; 30 (3): 377-384

  Abstract

  Although chronic renal insufficiency (CRI) is associated with increased cardiac and noncardiac mortality, there is limited data on the relationship between CRI and survival in patients with implantable cardioverter-defibrillators (ICDs), particularly across a wide range of renal function.We studied 507 consecutive patients receiving first-time ICDs from 1993-2003 at a single center. Preimplant serum creatinine measurements were used to determine glomerular filtration rate (GFR) and stage of chronic kidney disease (CKD). The primary outcome was time to death.During a mean follow-up of 4 years, all-cause mortality through completion of follow-up increased stepwise by GFR stage (I: 16%, II: 20%, III: 35%; IV: 40%; V: 50%; P < 0.001 for trend). After multivariate adjustment, CRI was independently associated with death (HR = 1.7, P = 0.02), as were a serum creatinine >or=2.0 mg/dL (HR 2.5, P = 0.003) and the presence of end-stage renal disease (HR 6.8; P < 0.001). For every 10-unit decrease in GFR, the adjusted hazard of death increased 12% (P = 0.04).The presence of CRI prior to implant is independently associated with increased mortality in patients receiving ICDs. The risk is proportional to the degree of renal dysfunction and is apparent even when GFR is only mildly reduced. Differences in mortality are observed within the first year of implant, and patients on dialysis are at highest risk. Because randomized trials of ICDs have not included large numbers of patients with moderate or severe renal disease, our findings may have important implications in prognosis and case selection of patients who otherwise meet current indications for ICD implantation.

  View details for Web of Science ID 000244886500011

  View details for PubMedID 17367357

• Regional left atrial voltage in patients with atrial fibrillation. Heart rhythm Marcus, G. M., Yang, Y., Varosy, P. D., Ordovas, K., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Scheinman, M. M., Olgin, J. E. 2007; 4 (2): 138-44

  Abstract

  Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis.The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium.Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude.The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05).Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls.

  View details for DOI 10.1016/j.hrthm.2006.10.017

  View details for PubMedID 17275746

  View details for PubMedCentralID PMC1868443

• Screening for coronary artery disease after mediastinal irradiation for Hodgkin's disease JOURNAL OF CLINICAL ONCOLOGY Heidenreich, P. A., Schnittger, I., Strauss, H. W., Vagelos, R. H., Lee, B. K., Mariscal, C. S., Tate, D. J., Horning, S. J., Hoppe, R. T., Hancock, S. L. 2007; 25 (1): 43-49

  Abstract

  Incidental cardiac irradiation during treatment of thoracic neoplasms has increased risks for subsequent acute myocardial infarction or sudden cardiac death. Identifying patients who have a high risk for a coronary event may decrease morbidity and mortality. The objective of this study was to evaluate whether stress imaging can identify severe, unsuspected coronary stenoses in patients who had prior mediastinal irradiation for Hodgkin's disease.We enrolled 294 outpatients observed at a tertiary care cancer treatment center after mediastinal irradiation doses 35 Gy for Hodgkin's disease who had no known ischemic cardiac disease. Patients underwent stress echocardiography and radionuclide perfusion imaging at one stress session. Coronary angiography was performed at the discretion of the physician.Among the 294 participants, 63 (21.4%) had abnormal ventricular images at rest, suggesting prior myocardial injury. During stress testing, 42 patients (14%) developed perfusion defects (n = 26), impaired wall motion (n = 8), or both abnormalities (n = 8). Coronary angiography showed stenosis 50% in 22 patients (55%), less than 50% in nine patients (22.5%), and no stenosis in nine patients (22.5%). Screening led to bypass graft surgery in seven patients. Twenty-three patients developed coronary events during a median of 6.5 years of follow-up, with 10 acute myocardial infarctions (two fatal).Stress-induced signs of ischemia and significant coronary artery disease are highly prevalent after mediastinal irradiation in young patients. Stress testing identifies asymptomatic individuals at high risk for acute myocardial infarction or sudden cardiac death.

  View details for DOI 10.1200/JCO.2006.07.0805

  View details for Web of Science ID 000243725900009

  View details for PubMedID 17194904

• Repeat transseptal catheterization after ablation for atrial fibrillation JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY Marcus, G. M., Ren, X., Tseng, Z. H., Badhwar, N., Lee, B. K., Lee, R. J., Foster, E., Olgin, J. E. 2007; 18 (1): 55-59

  Abstract

  A substantial number of patients require a second left atrial procedure after ablation for atrial fibrillation (AF), either for left atrial flutter or recurrent AF. The success and complication rates of repeat transseptal catheterization in these patients are unknown. The aim of this study was to determine the difficulty and/or success rates of repeat transseptal catheterization after left atrial ablation for AF.Consecutive patients undergoing repeat left atrial procedures after ablation for AF over a 1-year period were enrolled. Difficulties with, success rates, and complications of the first and second transseptal catheterizations were recorded. Sixteen patients underwent a repeat transseptal catheterization. Of the 4 in whom the first procedure was performed with an ablation catheter across a patent foramen ovale (PFO), 3 required a transseptal puncture for their repeat procedure. The remaining 12 underwent transseptal puncture without difficulty for their first procedure, and, despite the same operators for each patient, the repeat transseptal was noted to be difficult in 5. Of those 5, the transseptal puncture was unsuccessful due to increased interatrial septal thickness in 2 patients. One repeat transseptal attempt was aborted after posterior right atrial puncture with the transseptal needle occurred, attributed to distorted interatrial septal anatomy not observed prior to the first case.Compared with the first procedure, repeat transseptal catheterization after ablation for AF, whether initially performed across a PFO or via a transseptal puncture, is more difficult, less often successful, and potentially associated with more complications.

  View details for DOI 10.1111/j.1540-8167.2006.00657.x

  View details for Web of Science ID 000242833000013

  View details for PubMedID 17081207

• Prevalence, patterns of development, and prognosis of right bundle branch block in heart transplant recipients AMERICAN JOURNAL OF CARDIOLOGY Marcus, G. M., Hoang, K. L., Hunt, S. A., Chun, S. H., Lee, B. K. 2006; 98 (9): 1288-1290

  Abstract

  Right bundle branch block (RBBB) is the most common electrocardiographic abnormality in heart transplant recipients, but the cause remains unknown, data regarding the prognosis are conflicting, and all previous studies have been limited to <100 patients. This was a study of patients who underwent heart transplantation at Stanford University Medical Center from 1981 to 1995 with known outcomes and >or=2 available electrocardiograms (ECGs). Outcomes were assessed in those with and without conduction disturbances recorded from the ECGs closest to the time of transplantation and the most recent ECGs. Of the 322 heart transplant recipients studied, 141 (44%) died over a mean follow-up of 9 +/- 3.5 years, and 40 (13%) died of sudden cardiac death. In the first ECG obtained, a mean of 1.8 +/- 2.4 years after transplantation, 44 patients (14%) had incomplete RBBB and 26 (8%) had RBBB; in the second ECG, obtained a mean of 5.6 +/- 3.7 years after transplantation, 59 patients (18%) had incomplete RBBB and 63 (20%) had RBBB. Increasing time from transplantation was associated with a greater likelihood for RBBB on the first and second ECGs (p = 0.001 and p <0.0001, respectively). QRS duration, incomplete RBBB, RBBB, or the development of RBBB was not associated with mortality or sudden cardiac death. In conclusion, although RBBB was the most common electrocardiographic abnormality in our study, the prevalence was lower than previously reported. The cause of RBBB appears to be largely related to events that occur well after transplantation, and the prognosis is benign.

  View details for Web of Science ID 000241982200037

  View details for PubMedID 17056348

• Initiation of antidromic reciprocating tachycardia: What is the mechanism? HEART RHYTHM Marcus, G. M., Lee, B. K., Scheinman, M. M. 2006; 3 (7): 865

  View details for DOI 10.1016/j.hrthm.2006.03.014

  View details for Web of Science ID 000239045600025

  View details for PubMedID 16818224

• Diastolic dysfunction after mediastinal irradiation AMERICAN HEART JOURNAL Heidenreich, P. A., Hancock, S. L., Vagelos, R. H., Lee, B. K., Schnittger, I. 2005; 150 (5): 977-982

  Abstract

  Mediastinal irradiation is known to cause cardiac disease, but its effect on left ventricular diastolic function is unknown. The purpose of this study was to determine the prevalence of diastolic dysfunction and its association with prognosis in asymptomatic patients after mediastinal irradiation.We recruited 294 patients who had received at least 35 Gy to the mediastinum for treatment of Hodgkin disease. Each patient underwent resting echocardiography, stress echocardiography, and nuclear scintigraphy. Survival free from cardiac events was determined during 3.2 years of follow-up.The mean age of the included patients was 42 years, and 49% were male. Adequate measurements of diastolic function were obtained in 282 (97%) patients. Diastolic dysfunction was considered mild in 26 (9%) and moderate in 14 (5%). Exercise-induced ischemia was more common in patients with diastolic dysfunction (23%) than those with normal diastolic function (11%, P = .008). After adjustment for patient demographics, clinical characteristics, and radiation history, patients with diastolic dysfunction had worse event-free survival than patients with normal function (hazard ratio 1.66, 95% CI 1.06-2.4).There is a high prevalence of diastolic dysfunction in asymptomatic patients after mediastinal irradiation, and the presence of diastolic dysfunction is associated with stress-induced ischemia and a worse prognosis. Screening with Doppler echocardiography may be helpful in identifying patients at risk for subsequent cardiac events.

  View details for DOI 10.1016/j.ahj.2004.12.026

  View details for Web of Science ID 000233478800024

  View details for PubMedID 16290974

• A unique method by which to quantitate synchrony with equilibrium radionuclide angiography JOURNAL OF NUCLEAR CARDIOLOGY O'Connell, J. W., Schreck, C., Moles, M., Badwar, N., DeMarco, T., Olgin, J., Lee, B., Tseng, Z., Kumar, U., Botvinick, E. H. 2005; 12 (4): 441-450

  Abstract

  Cardiac resynchronization therapy (CRT) improves symptoms and the survival rate in patients with advanced heart failure by improving synchrony. However, CRT is not always successful, is costly, and is applied without individualization. There is no specific measure of synchrony. The goal of this study was to analyze new quantitative parameters of synchrony and compare them with established measures.Equilibrium radionuclide angiography, phase angle (Ø), and amplitude quantitate regional contraction timing and magnitude and are the basis for new synchrony (S) and entropy (E) parameters. S is the vector sum of all amplitudes based on the angular distribution of Ø divided by the scalar sum of the length of all vectors. Complete S equals 1, and its absence equals 0. E measures the disorder in the region of interest, is 1 with random contraction and 0 with full synchrony, and differentiates among differing contraction patterns. Left ventricular S and E were measured in 22 normal equilibrium radionuclide angiography studies, where regions of interest were drawn from the left ventricle, left atrium, and background to analyze model ventricles with normal wall motion (N), ventricles with aneurysm (An), ventricles with severe diffuse dysfunction (Diff), and ventricles with severe regional dysfunction (Reg). The new S and E parameters were highly reproducible and well differentiated among N, An, Diff, and Reg, which were not separated by SD Ø (SD of ventricular phase), which has gained popularity as a measure of synchrony.Unique scintigraphic parameters for the evaluation of ventricular synchrony were derived, and their added value was determine compared with established measures. Indications for pacemaker therapy now include the treatment of severe congestive heart failure (CHF). Atrial triggered biventricular pacemakers reduce CHF symptoms and prolong life in patients with cardiomyopathy, severe CHF, left ventricular (LV) ejection fraction (EF) lower than 35%, and QRS greater than 120 milliseconds. Such pacing, or cardiac resynchronization therapy (CRT), seeks to reduce the heterogeneity and increase the synchrony of ventricular activation, conduction, and contraction. CRT has improved hemodynamics, increased exercise tolerance, reduced symptoms and the need for hospitalization, reversed ventricular remodeling, and reduced the all-cause mortality rate in CHF. However, CRT is costly, fails to improve symptoms or activity level in more than 30% of patients, and is applied blindly without individualization or consideration of lead placement sight. A variety of echocardiographic methods have sought to measure synchrony and its serial changes with CRT. A recent study presented evidence of the poor reproducibility of several widely applied echocardiographic measurements by which to determine ventricular synchrony. Magnetic resonance imaging has excellent resolution of regional wall motion and has been applied to assess ventricular synchrony and its response to pacing therapy. However, these methods are complex and are not well established or widely available, and magnetic resonance imaging has not been widely applied after pacing. An accurate and reproducible method is needed by which to objectively measure regional ventricular synchrony. Phase image analysis, a functional method based on the first Fourier harmonic fit of the gated blood pool time versus radioactivity curve, generates the parameters of amplitude (A), which parallels the extent of regional ventricular contraction or stroke volume, and phase angle (Ø), which represents the timing of regional contraction. It was applied early with demonstrated reproducibility to show the linkage between electrical and mechanical dyssynchrony and to characterize the contraction pattern in heart failure and its alteration with CRT. The SD of ventricular Ø, applied as a marker of synchrony, has been shown to demonstrate the beneficial effects of biventricular pacing, and its strong prognostic value has been shown in patients with congestive cardiomyopathy and CHF, superior to LVEF. The SD Ø may not be optimal for synchrony evaluation. We sought improved, more sensitive parameters to better differentiate synchrony among the spectrum of possible patterns of dyssynergy. We derived, initially evaluated, and here present new synchrony (S) and entropy (E) parameters, based on the phase method, to quantitate regional and global ventricular synchrony and applied them in simulation and clinical protocols.

  View details for DOI 10.1016/j.nuclcard.2005.05.006

  View details for Web of Science ID 000230993600011

  View details for PubMedID 16084433

• Usefulness of a ventricular extrastimulus from the summit of the ventricular septum in diagnosis of septal accessory pathway in patients with supraventricular tachycardia AMERICAN JOURNAL OF CARDIOLOGY Matsushita, T., Badhwar, N., Collins, K. K., Van Hare, G. F., Barbato, G., Lee, B. K., Lee, R. J., Scheinman, M. M. 2004; 93 (5): 643-646

  Abstract

  To compare usefulness of a ventricular extrastimulus (VES) from the right ventricular (RV) apex versus the RV septum in patients with a septal accessory pathway (AP), VES was applied from the RV apex and the summit of the RV septum in patients with septal APs. A VES from the RV apex and from the summit was diagnostic of the presence of an AP in 13 of 28 patients (83%) and in 10 of 12 patients, respectively (46% p <0.05), and VES proved an AP as a part of the tachycardia circuit in 5 of 28 patients (18%) and 6 of 12 patients, respectively (50%, p <0.05). A VES during His bundle refractoriness from the RV summit increases the diagnostic yield for both the presence of an AP and its participation in the tachycardia circuit with respect to RV apical VES.

  View details for DOI 10.1016/j.amjcard.2003.11.041

  View details for Web of Science ID 000220075800030

  View details for PubMedID 14996601

• Asymptomatic cardiac disease following mediastinal irradiation JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Heidenreich, P. A., Hancock, S. L., Lee, B. K., Mariscal, C. S., Schnittger, I. 2003; 42 (4): 743-749

  Abstract

  This study was designed to evaluate the potential benefit of screening previously irradiated patients with echocardiography.Mediastinal irradiation is known to cause cardiac disease. However, the prevalence of asymptomatic cardiac disease and the potential for intervention before symptom development are unknown.We recruited 294 asymptomatic patients (mean age 42 +/- 9 years, 49% men, mean mantle irradiation dose 43 +/- 0.3 Gy) treated with at least 35 Gy to the mediastinum for Hodgkin's disease. After providing written consent, each patient underwent electrocardiography and transthoracic echocardiography. Valvular disease was common and increased with time following irradiation. Patients who had received irradiation more than 20 years before evaluation had significantly more mild or greater aortic regurgitation (60% vs. 4%, p < 0.0001), moderate or greater tricuspid regurgitation (4% vs. 0%, p = 0.06), and aortic stenosis (16% vs. 0%, p = 0.0008) than those who had received irradiation within 10 years. The number needed to screen to detect one candidate for endocarditis prophylaxis was 13 (95% confidence interval [CI] 7 to 44) for patients treated within 10 years and 1.6 (95% CI 1.3 to 1.9) for those treated at least 20 years ago. Compared with the Framingham Heart Study population, mildly reduced left ventricular fractional shortening (<30%) was more common (36% vs. 3%), and age- and gender-adjusted left ventricular mass was lower (90 +/- 27 g/m vs. 117 g/m) in irradiated patients.There is a high prevalence of asymptomatic heart disease in general, and aortic valvular disease in particular, following mediastinal irradiation. Screening echocardiography should be considered for patients with a history of mediastinal irradiation.

  View details for DOI 10.1016/S0735-1097(03)00759-9

  View details for Web of Science ID 000184780600027

  View details for PubMedID 12932613

• Images in clinical medicine. Calcified left ventricular aneurysm. The New England journal of medicine Lee, B. K., Atwood, J. E. 2003; 348 (10): 918

  View details for DOI 10.1056/NEJMicm010137

  View details for PubMedID 12621136

• Cost-effectiveness of radiofrequency ablation for supraventricular tachycardia ANNALS OF INTERNAL MEDICINE Cheng, C. H., Sanders, G. D., Hlatky, M. A., Heidenreich, P., McDonald, K. M., Lee, B. K., Larson, M. S., Owens, D. K. 2000; 133 (11): 864-876

  Abstract

  Radiofrequency ablation is an established but expensive treatment option for many forms of supraventricular tachycardia. Most cases of supraventricular tachycardia are not life-threatening; the goal of therapy is therefore to improve the patient's quality of life.To compare the cost-effectiveness of radiofrequency ablation with that of medical management of supraventricular tachycardia.Markov model.Costs were estimated from a major academic hospital and the literature, and treatment efficacy was estimated from reports from clinical studies at major medical centers. Probabilities of clinical outcomes were estimated from the literature. To account for the effect of radiofrequency ablation on quality of life, assessments by patients who had undergone the procedure were used.Cohort of symptomatic patients who experienced 4.6 unscheduled visits per year to an emergency department or a physician's office while receiving long-term drug therapy for supraventricular tachycardia.Patient lifetime.Societal.Initial radiofrequency ablation, long-term antiarrhythmic drug therapy, and treatment of acute episodes of arrhythmia with antiarrhythmic drugs.Costs, quality-adjusted life-years, life-years, and marginal cost-effectiveness ratios.Among patients who have monthly episodes of supraventricular tachycardia, radiofrequency ablation was the most effective and least expensive therapy and therefore dominated the drug therapy options. Radiofrequency ablation improved quality-adjusted life expectancy by 3.10 quality-adjusted life-years and reduced lifetime medical expenditures by $27 900 compared with long-term drug therapy. Long-term drug therapy was more effective and had lower costs than episodic drug therapy.The findings were highly robust over substantial variations in assumptions about the efficacy and complication rate of radiofrequency ablation, including analyses in which the complication rate was tripled and efficacy was decreased substantially.Radiofrequency ablation substantially improves quality of life and reduces costs when it is used to treat highly symptomatic patients. Although the benefit of radiofrequency ablation has not been studied in less symptomatic patients, a small improvement in quality of life is sufficient to give preference to radiofrequency ablation over drug therapy.

  View details for PubMedID 11103056

• An evaluation of beta-blockers, calcium antagonists, nitrates, and alternative therapies for stable angina. Evidence report/technology assessment (Summary) Heidenreich, P. A., McDonald, K. M., Hastie, T., Fadel, B., Hagan, V., Lee, B. K., Hlatky, M. A. 1999: 1-2

  View details for PubMedID 11925969

• Meta-analysis of trials comparing beta-blockers, calcium antagonists, and nitrates for stable angina JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Heidenreich, P. A., McDonald, K. M., Hastie, T., Fadel, B., Hagan, V., Lee, B. K., Hlatky, M. A. 1999; 281 (20): 1927-1936

  Abstract

  Which drug is most effective as a first-line treatment for stable angina is not known.To compare the relative efficacy and tolerability of treatment with beta-blockers, calcium antagonists, and long-acting nitrates for patients who have stable angina.We identified English-language studies published between 1966 and 1997 by searching the MEDLINE and EMBASE databases and reviewing the bibliographies of identified articles to locate additional relevant studies.Randomized or crossover studies comparing antianginal drugs from 2 or 3 different classes (beta-blockers, calcium antagonists, and long-acting nitrates) lasting at least 1 week were reviewed. Studies were selected if they reported at least 1 of the following outcomes: cardiac death, myocardial infarction, study withdrawal due to adverse events, angina frequency, nitroglycerin use, or exercise duration. Ninety (63%) of 143 identified studies met the inclusion criteria.Two independent reviewers extracted data from selected articles, settling any differences by consensus. Outcome data were extracted a third time by 1 of the investigators. We combined results using odds ratios (ORs) for discrete data and mean differences for continuous data. Studies of calcium antagonists were grouped by duration and type of drug (nifedipine vs nonnifedipine).Rates of cardiac death and myocardial infarction were not significantly different for treatment with beta-blockers vs calcium antagonists (OR, 0.97; 95% confidence interval [CI], 0.67-1.38; P = .79). There were 0.31 (95% CI, 0.00-0.62; P = .05) fewer episodes of angina per week with beta-blockers than with calcium antagonists. beta-Blockers were discontinued because of adverse events less often than were calcium antagonists (OR, 0.72; 95% CI, 0.60-0.86; P<.001). The differences between beta-blockers and calcium antagonists were most striking for nifedipine (OR for adverse events with beta-blockers vs nifedipine, 0.60; 95% CI, 0.47-0.77). Too few trials compared nitrates with calcium antagonists or beta-blockers to draw firm conclusions about relative efficacy.beta-Blockers provide similar clinical outcomes and are associated with fewer adverse events than calcium antagonists in randomized trials of patients who have stable angina.

  View details for Web of Science ID 000080427300033

  View details for PubMedID 10349897

• Lemierre's syndrome SOUTHERN MEDICAL JOURNAL Lee, B. K., LOPEZ, F., Genovese, M., Loutit, J. S. 1997; 90 (6): 640-643

  Abstract

  Lemierre's syndrome is an acute medical condition characterized by anaerobic oropharyngeal infection leading to septic thrombophlebitis of the internal jugular vein. The illness is often complicated by septic pulmonary emboli and distant metastatic infections. Treatment consists of surgical drainage of purulent collections and long-term intravenous antibiotic therapy. Although Lemierre's syndrome is rare, it is potentially fatal and remains an important entity for clinicians to recognize and treat appropriately.

  View details for Web of Science ID A1997XE84400013

  View details for PubMedID 9191743

• Impaired endothelium-dependent vasodilation in patients with insulin-dependent diabetes mellitus. Circulation Johnstone, M. T., Creager, S. J., Scales, K. M., Cusco, J. A., Lee, B. K., Creager, M. A. 1993; 88 (6): 2510-6

  Abstract

  Endothelium-dependent vasodilation is abnormal in experimental models of diabetes mellitus. We postulated that abnormalities of endothelial function are also present in patients with insulin-dependent diabetes mellitus and may contribute to the pathogenesis of vascular disease in these individuals.Vascular reactivity was measured in the forearm resistance vessels of 15 patients with insulin-dependent diabetes mellitus and 16 age-matched normal subjects. No patient had hypertension or dyslipidemia. Each subject was pretreated with aspirin to inhibit endogenous production of prostanoids. Methacholine chloride (0.3 to 10 micrograms/min) was administered via the brachial artery to assess endothelium-dependent vasodilation. Sodium nitroprusside (0.3 to 10 micrograms/min) and verapamil (10 to 300 micrograms/min) were infused intra-arterially to assess endothelium-independent vasodilation; phenylephrine (0.3 to 3 micrograms/min) was administered to examine vasoconstrictor responsiveness. Forearm blood flow was determined by venous occlusion plethysmography, and dose-response curves were generated for each drug. Basal forearm blood flow in diabetic and normal subjects was comparable (2.6 +/- 0.2 versus 2.1 +/- 0.3 mL x 100 mL-1 x min-1, respectively; P = NS). The forearm vasodilative response to methacholine was less in diabetic than in normal subjects. At the highest dose of methacholine, the forearm blood flow increased 9.5 +/- 1.1 mL x 100 mL-1 x min-1 in diabetic subjects and 15.3 +/- 1.4 mL.100 mL-1 x min-1 in normal subjects (P < .01). The forearm blood flow responses to nitroprusside and verapamil and the forearm vasoconstrictor responses to phenylephrine were similar in diabetic and healthy subjects. In diabetic subjects, endothelium-dependent vasodilation correlated inversely with serum insulin concentration but not with glucose concentration, glycosylated hemoglobin, or duration of diabetes.Endothelium-dependent vasodilation is abnormal in forearm resistance vessels of patients with insulin-dependent diabetes mellitus. This abnormality may be relevant to the high prevalence of vascular disease that occurs in these individuals.

  View details for DOI 10.1161/01.cir.88.6.2510

  View details for PubMedID 8080489