Byron Lee

All Publications

• 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. M., Lee, S. Y., Lee, B. K., Seshasai, S. 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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

• 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