Dr. Albert “A.J.” Rogers, MD, MBA is a clinical cardiac electrophysiologist and cardiovascular research scientist at Stanford University. He is trained in cardiac electrophysiology, biomedical and software engineering, signal processing, and data science. Clinically, his expertise is in complex arrhythmia mapping and ablation, including atrial fibrillation, supraventricular tachycardia, and ventricular tachycardia. He also performs cardiac device implantation of leadless pacemakers, conduction system pacing, cardiac resynchronization therapy, defibrillators, and event recorders. In research, he is supported by the National Institutes of Health (NIH) and other agencies to investigate pathophysiology, diagnosis, and treatment of heart rhythm disorders. His research explores the mechanisms of cardiac arrhythmia using signal processing, machine learning, and in silico modeling. He has over 10 years of medical technology innovation and development experience ranging from design to preclinical and clinical studies.

Clinical Focus

  • Cardiovascular Medicine
  • Cardiac Arrhythmia
  • Cardiovascular Disease
  • Catheter Ablation
  • Implantable Cardioverter Defibrillators
  • Supraventricular Tachycardia
  • Atrial Fibrillation
  • Ventricular Tachycardias
  • Sudden Cardiac Death

Academic Appointments

Honors & Awards

  • SVT Pioneer, Center of Excellence, Arrhythmia Alliance (2021)
  • 2020 Heart Rhythm Society Young Investigator Award Finalist: Basic Science, Heart Rhythm Society (2020)
  • Teaching Tomorrow’s Teachers (3T), Boston Scientific (2020)
  • Ruth L Kirshstein National Research Service Award (NRSA) Postdoctoral Fellowship, NIH/NHLBI (2018)
  • Stanford Society for Physician Scholars Research Award, Stanford University School of Medicine (2018)
  • The Heart Rhythm Society Clinical Research Award in Honor of Mark Josephson and Hein Wellens, Heart Rhythm Society (2018)
  • Alpha Omega Alpha, National Medical Honor Society, University of North Carolina School of Medicine (2014)
  • Beta Gamma Sigma, National Scholastic Business Honor Society, University of North Carolina: Kenan-Flagler Business School (2014)
  • John B. Graham Research Society, University of North Carolina School of Medicine (2011)
  • Eugene S. Mayer Community Service Honor Society, University of North Carolina School of Medicine (2010)
  • Departmental Distinction in Biomedical Engineering, Duke University (2009)
  • Pratt Undergraduate Research Award, Duke University (2008)

Professional Education

  • Fellowship: Stanford University Clinical Cardiac Electrophysiology Fellowship (2022) CA
  • Board Certification: American Board of Internal Medicine, Cardiovascular Disease (2020)
  • Fellowship: Stanford University Cardiovascular Medicine Fellowship (2020) CA
  • Board Certification: American Board of Internal Medicine, Internal Medicine (2017)
  • Residency: Stanford University Internal Medicine Residency (2016) CA
  • Medical Education: University of North Carolina School of Medicine (2014) NC
  • M.D., University of North Carolina, Medicine (2014)
  • M.B.A., UNC Kenan-Flagler Business School, Healthcare Entrepreneurship (2014)
  • B.S.E., Duke University, Biomedical Engineering, Chemistry, Medicine (2009)


  • Stephen C. Masson, Michael Cuchiara, Efrain A. Miranda, Richard A. Glenn, AJ Rogers. "United States Patent US20170189642A1 Systems and methods for neuromodulation therapy of the sympathetic and parasympathetic cardiac nerves", Interventional Autonomics Corporation, Mar 9, 2015

Clinical Trials

  • HEAL-IST IDE Trial Recruiting

    Inappropriate Sinus Tachycardia (IST) is a prevalent and debilitating condition in otherwise healthy younger patients, resulting in significant loss of quality of life, lacking effective treatment options or systematic clinical evidence to support a therapy. The primary objective of this clinical trial is to evaluate the safety and effectiveness of a hybrid sinus node sparing ablation procedure for the treatment of symptomatic drug refractory or drug intolerant IST.

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Graduate and Fellowship Programs

All Publications

  • Machine Learning-Enabled Multimodal Fusion of Intra-Atrial and Body Surface Signals in Prediction of Atrial Fibrillation Ablation Outcomes. Circulation. Arrhythmia and electrophysiology Tang, S., Razeghi, O., Kapoor, R., Alhusseini, M. I., Fazal, M., Rogers, A. J., Rodrigo Bort, M., Clopton, P., Wang, P., Rubin, D., Narayan, S. M., Baykaner, T. 2022: 101161CIRCEP122010850


    BACKGROUND: Machine learning is a promising approach to personalize atrial fibrillation management strategies for patients after catheter ablation. Prior atrial fibrillation ablation outcome prediction studies applied classical machine learning methods to hand-crafted clinical scores, and none have leveraged intracardiac electrograms or 12-lead surface electrocardiograms for outcome prediction. We hypothesized that (1) machine learning models trained on electrograms or ECG signals can perform better at predicting patient outcomes after atrial fibrillation ablation than existing clinical scores and (2) multimodal fusion of electrogram, ECG, and clinical features can further improve the prediction of patient outcomes.METHODS: Consecutive patients who underwent catheter ablation between 2015 and 2017 with panoramic left atrial electrogram before ablation and clinical follow-up for at least 1 year following ablation were included. Convolutional neural network and a novel multimodal fusion framework were developed for predicting 1-year atrial fibrillation recurrence after catheter ablation from electrogram, ECG signals, and clinical features. The models were trained and validated using 10-fold cross-validation on patient-level splits.RESULTS: One hundred fifty-six patients (64.5±10.5 years, 74% male, 42% paroxysmal) were analyzed. Using electrogram signals alone, the convolutional neural network achieved an area under the receiver operating characteristics curve of 0.731, outperforming the existing APPLE scores (area under the receiver operating characteristics curve=0.644) and CHA2DS2-VASc scores (area under the receiver operating characteristics curve=0.650). Similarly using 12-lead ECG alone, the convolutional neural network achieved an AUROC of 0.767. Combining electrogram, ECG, and clinical features, the fusion model achieved an AUROC of 0.859, outperforming single and dual modality models.CONCLUSIONS: Deep neural networks trained on electrogram or ECG signals improved the prediction of catheter ablation outcome compared with existing clinical scores, and fusion of electrogram, ECG, and clinical features further improved the prediction. This suggests the promise of using machine learning to help treatment planning for patients after catheter ablation.

    View details for DOI 10.1161/CIRCEP.122.010850

    View details for PubMedID 35867397

  • Mapping Atrial Fibrillation After Surgical Therapy to Guide Endocardial Ablation. Circulation. Arrhythmia and electrophysiology Bhatia, N. K., Shah, R. L., Deb, B., Pong, T., Kapoor, R., Rogers, A., Badhwar, N., Brodt, C., Wang, P. J., Narayan, S. M., Lee, A. M. 2022: 101161CIRCEP121010502


    Surgical ablation for atrial fibrillation (AF) can be effective, yet has mixed results. It is important to improve the success of AF surgery, yet unclear which endocardial lesions will best augment surgical lesion sets in individual patients. We addressed this question by systematically mapping AF endocardially after surgical ablation and relating findings to early recurrence.We studied 81 consecutive patients undergoing epicardial surgical ablation (stage 1 hybrid), of whom 64 proceeded to endocardial catheter mapping and ablation (stage 2). Stage 2 comprised high-density mapping of pulmonary vein (PV) or posterior wall (PW) reconnections, low-voltage zones (LVZs), and potential localized AF drivers. We related findings to postsurgical recurrence of AF.Mapping at stage 2 revealed PW isolation reconnection in 59.4%, PV isolation reconnection in 28.1%, and LVZ in 42.2% of patients. Postsurgical recurrence of AF occurred in 36 patients (56.3%), particularly those with long-standing persistent AF (P=0.017), but had no relationship to reconnection of PVs (P=0.53) or PW isolation (P=0.75) when compared with those without postsurgical recurrence of AF. LVZs were more common in patients with postsurgical recurrence of AF (P=0.002), long-standing persistent AF (P=0.002), advanced age (P=0.03), and elevated CHA2DS2-VASc (P=0.046). AF mapping revealed 4.4±2.7 localized focal/rotational sites near and also remote from PV or PW reconnection. After ablation at patient-specific targets, arrhythmia freedom at 1 year was 81.0% including and 73.0% excluding previously ineffective antiarrhythmic medications.After surgical ablation, AF may recur by several modes including recovery of PW or PV isolation, mechanisms related to localized LVZ, or other sustaining mechanisms. LVZs are more common in patients at high clinical risk for recurrence. Patient-specific targeting of these mechanisms yields excellent long-term outcomes from hybrid ablation.

    View details for DOI 10.1161/CIRCEP.121.010502

    View details for PubMedID 35622437

  • Modeling Effects of Immunosuppressive Drugs on Human Hearts Using Induced Pluripotent Stem Cell-Derived Cardiac Organoids and Single-Cell RNA Sequencing. Circulation Sallam, K., Thomas, D., Gaddam, S., Lopez, N., Beck, A., Beach, L., Rogers, A. J., Zhang, H., Chen, I. Y., Ameen, M., Hiesinger, W., Teuteberg, J. J., Rhee, J. W., Wang, K. C., Sayed, N., Wu, J. C. 2022; 145 (17): 1367-1369

    View details for DOI 10.1161/CIRCULATIONAHA.121.054317

    View details for PubMedID 35467958

  • Atrial fibrillation signatures on intracardiac electrograms identified by deep learning. Computers in biology and medicine Rodrigo, M., Alhusseini, M. I., Rogers, A. J., Krittanawong, C., Thakur, S., Feng, R., Ganesan, P., Narayan, S. M. 2022; 145: 105451


    BACKGROUND: Automatic detection of atrial fibrillation (AF) by cardiac devices is increasingly common yet suboptimally groups AF, flutter or tachycardia (AT) together as 'high rate events'. This may delay or misdirect therapy.OBJECTIVE: We hypothesized that deep learning (DL) can accurately classify AF from AT by revealing electrogram (EGM) signatures.METHODS: We studied 86 patients in whom the diagnosis of AF or AT was established at electrophysiological study (25 female, 65±11 years). Custom DL architectures were trained to identify AF using N=29,340 unipolar and N=23,760 bipolar EGM segments. We compared DL to traditional classifiers based on rate or regularity. We explained DL using computer models to assess the impact of controlled variations in shape, rate and timing on AF/AT classification in 246,067 EGMs reconstructed from clinical data.RESULTS: DL identified AF with AUC of 0.97±0.04 (unipolar) and 0.92±0.09 (bipolar). Rule-based classifiers misclassified 10-12% of cases. DL classification was explained by regularity in EGM shape (13%) or timing (26%), and rate (60%; p<0.001), and also by a set of unipolar EGM shapes that classified as AF independent of rate or regularity. Overall, the optimal AF 'fingerprint' comprised these specific EGM shapes, >15% timing variation, <0.48 correlation in beat-to-beat EGM shapes and CL<190ms (p<0.001).CONCLUSIONS: Deep learning of intracardiac EGMs can identify AF or AT via signatures of rate, regularity in timing or shape, and specific EGM shapes. Future work should examine if these signatures differ between different clinical subpopulations with AF.

    View details for DOI 10.1016/j.compbiomed.2022.105451

    View details for PubMedID 35429831

  • TARGETING SYNCHRONIZED ELECTROGRAM ISLANDS WITHIN ATRIAL FIBRILLATION FOR ABLATION Ganesan, P., Deb, B., Feng, R., Rodrigo, M., Ruiperez-Campillo, S., Bhatia, N. K., Rogers, A. J., Clopton, P., Rappel, W., Narayan, S. M. ELSEVIER SCIENCE INC. 2022: 3
  • A MORPHOLOGICAL OPERATION-BASED APPROACH TO AUTOMATICALLY SEPARATE AND LABEL LEFT ATRIUM BODY AND PULMONARY VEINS Feng, R., Ganesan, P., Deb, B., Rogers, A. J., Ruiperez-Campillo, S., Rodrigo, M., Zaharia, M., Clopton, P., Rappel, W., Narayan, S. M. ELSEVIER SCIENCE INC. 2022: 1244
  • Wide Complex QRS During Sotalol Administration. JAMA cardiology Rogers, A. J., Wang, P. J., Badhwar, N. 1800

    View details for DOI 10.1001/jamacardio.2021.5788

    View details for PubMedID 35080582

  • Immediate and Delayed Response of Simulated Human Atrial Myocytes to Clinically-Relevant Hypokalemia FRONTIERS IN PHYSIOLOGY Clerx, M., Mirams, G. R., Rogers, A. J., Narayan, S. M., Giles, W. R. 2021; 12: 651162


    Although plasma electrolyte levels are quickly and precisely regulated in the mammalian cardiovascular system, even small transient changes in K+, Na+, Ca2+, and/or Mg2+ can significantly alter physiological responses in the heart, blood vessels, and intrinsic (intracardiac) autonomic nervous system. We have used mathematical models of the human atrial action potential (AP) to explore the electrophysiological mechanisms that underlie changes in resting potential (Vr) and the AP following decreases in plasma K+, [K+]o, that were selected to mimic clinical hypokalemia. Such changes may be associated with arrhythmias and are commonly encountered in patients (i) in therapy for hypertension and heart failure; (ii) undergoing renal dialysis; (iii) with any disease with acid-base imbalance; or (iv) post-operatively. Our study emphasizes clinically-relevant hypokalemic conditions, corresponding to [K+]o reductions of approximately 1.5 mM from the normal value of 4 to 4.5 mM. We show how the resulting electrophysiological responses in human atrial myocytes progress within two distinct time frames: (i) Immediately after [K+]o is reduced, the K+-sensing mechanism of the background inward rectifier current (IK1) responds. Specifically, its highly non-linear current-voltage relationship changes significantly as judged by the voltage dependence of its region of outward current. This rapidly alters, and sometimes even depolarizes, Vr and can also markedly prolong the final repolarization phase of the AP, thus modulating excitability and refractoriness. (ii) A second much slower electrophysiological response (developing 5-10 minutes after [K+]o is reduced) results from alterations in the intracellular electrolyte balance. A progressive shift in intracellular [Na+]i causes a change in the outward electrogenic current generated by the Na+/K+ pump, thereby modifying Vr and AP repolarization and changing the human atrial electrophysiological substrate. In this study, these two effects were investigated quantitatively, using seven published models of the human atrial AP. This highlighted the important role of IK1 rectification when analyzing both the mechanisms by which [K+]o regulates Vr and how the AP waveform may contribute to "trigger" mechanisms within the proarrhythmic substrate. Our simulations complement and extend previous studies aimed at understanding key factors by which decreases in [K+]o can produce effects that are known to promote atrial arrhythmias in human hearts.

    View details for DOI 10.3389/fphys.2021.651162

    View details for Web of Science ID 000659214100001

    View details for PubMedID 34122128

    View details for PubMedCentralID PMC8188899

  • IDENTIFICATION OF AREAS OF ORGANIZED 1:1 ACTIVITY IN ATRIAL FIBRILLATION IN PATIENTS POST MAZE SURGERY Bhatia, N. K., Shah, R., Ganesan, P., Rogers, A., Pong, T., Purewal, S., Baykaner, T., Wang, P., Lee, A., Rappel, W., Narayan, S. ELSEVIER SCIENCE INC. 2021: 333
  • PROBING MACHINE LEARNING TO SEPARATE ATRIAL FIBRILLATION FROM OTHER ARRHYTHMIAS Rodrigo, M., Rogers, A., Ganesan, P., Alhusseini, M., Krittanawong, C., Narayan, S. ELSEVIER SCIENCE INC. 2021: 3410
  • CONSISTENT SPATIOTEMPORAL VECTORS IN ATRIAL FIBRILLATION PREDICT RESPONSE TO ABLATION Ganesan, P., Bhatia, N., Beck, T. C., Ravi, N., Rogers, A., Krummen, D., Wang, P., Rappel, W., Narayan, S. ELSEVIER SCIENCE INC. 2021: 334
  • Non-invasive Spatial Mapping of Frequencies in Atrial Fibrillation: Correlation With Contact Mapping FRONTIERS IN PHYSIOLOGY Rodrigo, M., Waddell, K., Magee, S., Rogers, A. J., Alhusseini, M., Hernandez-Romero, I., Costoya-Sanchez, A., Liberos, A., Narayan, S. M. 2021; 11
  • Competing Risks in Patients with Primary Prevention Implantable Cardioverter-Defibrillators: Global Electrical Heterogeneity and Clinical Outcomes (GEHCO) Study. Heart rhythm Waks, J. W., Haq, K. T., Tompkins, C. n., Rogers, A. J., Ehdaie, A. n., Bender, A. n., Minnier, J. n., Dalouk, K. n., Howell, S. n., Peiris, A. n., Raitt, M. n., Narayan, S. M., Chugh, S. S., Tereshchenko, L. G. 2021


    Global electrical heterogeneity (GEH) is associated with sudden cardiac death in the general population. Its utility in patients with systolic heart failure (HF) who are candidates for primary prevention (PP) implantable cardioverter-defibrillators (ICDs) is unclear.To investigate whether GEH is associated with sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) leading to appropriate ICD therapies in HF patients with PP ICDs.We conducted a multicenter retrospective cohort study. GEH was measured by spatial ventricular gradient (SVG) direction (azimuth and elevation) and magnitude, QRS-T angle, and sum absolute QRST integral (SAIQRST) on pre-implant 12-lead ECGs. Survival analysis using cause-specific hazard functions compared the strength of associations with two competing outcomes: sustained VT/VF leading to appropriate ICD therapies and all-cause death without appropriate ICD therapies.We analyzed 2,668 patients (age 63±12y; 23% female; 78% white; 43% nonischemic cardiomyopathy (NICM); left ventricular ejection fraction 28±11% from 6 academic medical centers). After adjustment for demographic, clinical, device, and traditional ECG characteristics, SVG elevation (Hazard Ratio (HR) per 1 standard deviation (SD) 1.14 (95% CI 1.04-1.25); P=0.004), SVG azimuth (HR per 1 SD 1.12(1.01-1.24); P=0.039); SVG magnitude (HR per 1 SD 0.75(0.66-0.85); P<0.0001), and QRS-T angle (HR per 1 SD 1.21 (95% CI 1.08-1.36); P=0.001) were associated with appropriate ICD therapies. SAIQRST had different associations in infarct-related [HR 1.29(1.04-1.60)] and NICM [HR 0.78(0.62-0.96); Pinteraction=0.022].In patients with PP ICDs, GEH is independently associated with appropriate ICD therapies. The SVG vector points in distinctly different directions in patients with two competing outcomes.

    View details for DOI 10.1016/j.hrthm.2021.03.006

    View details for PubMedID 33684549

  • Deep Neural Network Trained on Surface ECG Improves Diagnostic Accuracy of Prior Myocardial Infarction Over Q Wave Analysis Yildirim, O., Baloglu, U. B., Talo, M., Ganesan, P., Tung, J. S., Kang, G., Tooley, J., Alhusseini, M., Baykaner, T., Wang, P. J., Perez, M., Tereshchenko, L., Narayan, S. M., Rogers, A. J., IEEE IEEE. 2021
  • Arrhythmia Patterns in Patients on Ibrutinib. Frontiers in cardiovascular medicine Fazal, M., Kapoor, R., Cheng, P., Rogers, A. J., Narayan, S. M., Wang, P., Witteles, R. M., Perino, A. C., Baykaner, T., Rhee, J. 1800; 8: 792310


    Introduction: Ibrutinib, a Bruton's tyrosine kinase inhibitor (TKI) used primarily in the treatment of hematologic malignancies, has been associated with increased incidence of atrial fibrillation (AF), with limited data on its association with other tachyarrhythmias. There are limited reports that comprehensively analyze atrial and ventricular arrhythmia (VA) burden in patients on ibrutinib. We hypothesized that long-term event monitors could reveal a high burden of atrial and VAs in patients on ibrutinib. Methods: A retrospective data analysis at a single center using electronic medical records database search tools and individual chart review was conducted to identify consecutive patients who had event monitors while on ibrutinib therapy. Results: Seventy-two patients were included in the analysis with a mean age of 76.9 ± 9.9 years and 13 patients (18%) had a diagnosis of AF prior to the ibrutinib therapy. During ibrutinib therapy, most common arrhythmias documented were non-AF supraventricular tachycardia (n = 32, 44.4%), AF (n = 32, 44%), and non-sustained ventricular tachycardia (n = 31, 43%). Thirteen (18%) patients had >1% premature atrial contraction burden; 16 (22.2%) patients had >1% premature ventricular contraction burden. In 25% of the patients, ibrutinib was held because of arrhythmias. Overall 8.3% of patients were started on antiarrhythmic drugs during ibrutinib therapy to manage these arrhythmias. Conclusions: In this large dataset of ambulatory cardiac monitors on patients treated with ibrutinib, we report a high prevalence of atrial and VAs, with a high incidence of treatment interruption secondary to arrhythmias and related symptoms. Further research is warranted to optimize strategies to diagnose, monitor, and manage ibrutinib-related arrhythmias.

    View details for DOI 10.3389/fcvm.2021.792310

    View details for PubMedID 35047578

  • Three dimensional reconstruction to visualize atrial fibrillation activation patterns on curved atrial geometry. PloS one Abad, R., Collart, O., Ganesan, P., Rogers, A. J., Alhusseini, M. I., Rodrigo, M., Narayan, S. M., Rappel, W. 2021; 16 (4): e0249873


    BACKGROUND: The rotational activation created by spiral waves may be a mechanism for atrial fibrillation (AF), yet it is unclear how activation patterns obtained from endocardial baskets are influenced by the 3D geometric curvature of the atrium or 'unfolding' into 2D maps. We develop algorithms that can visualize spiral waves and their tip locations on curved atrial geometries. We use these algorithms to quantify differences in AF maps and spiral tip locations between 3D basket reconstructions, projection onto 3D anatomical shells and unfolded 2D surfaces.METHODS: We tested our algorithms in N = 20 patients in whom AF was recorded from 64-pole baskets (Abbott, CA). Phase maps were generated by non-proprietary software to identify the tips of spiral waves, indicated by phase singularities. The number and density of spiral tips were compared in patient-specific 3D shells constructed from the basket, as well as 3D maps from clinical electroanatomic mapping systems and 2D maps.RESULTS: Patients (59.4±12.7 yrs, 60% M) showed 1.7±0.8 phase singularities/patient, in whom ablation terminated AF in 11/20 patients (55%). There was no difference in the location of phase singularities, between 3D curved surfaces and 2D unfolded surfaces, with a median correlation coefficient between phase singularity density maps of 0.985 (0.978-0.990). No significant impact was noted by phase singularities location in more curved regions or relative to the basket location (p>0.1).CONCLUSIONS: AF maps and phase singularities mapped by endocardial baskets are qualitatively and quantitatively similar whether calculated by 3D phase maps on patient-specific curved atrial geometries or in 2D. Phase maps on patient-specific geometries may be easier to interpret relative to critical structures for ablation planning.

    View details for DOI 10.1371/journal.pone.0249873

    View details for PubMedID 33836026

  • Electrical Substrate Ablation for Refractory Ventricular Fibrillation: Results of the AVATAR Study. Circulation. Arrhythmia and electrophysiology Krummen, D. E., Ho, G. n., Hoffmayer, K. S., Schweis, F. n., Baykaner, T. n., Rogers, A. J., Han, F. T., Hsu, J. C., Viswanathan, M. N., Wang, P. J., Rappel, W. J., Narayan, S. M. 2021


    Background - Refractory ventricular fibrillation (VF) is a challenging clinical entity, for which ablation of triggering premature ventricular complexes (PVCs) is described. When PVCs are infrequent and multifocal, the optimal treatment strategy is uncertain. Methods - We prospectively enrolled consecutive patients presenting with multiple ICD shocks for VF refractory to antiarrhythmic drug therapy, exhibiting infrequent (≤3%), multifocal PVCs (≥3 morphologies). Procedurally, VF was induced with rapid pacing and mapped, identifying sites of conduction slowing and rotation or rapid focal activation. VF electrical substrate ablation (VESA) was then performed. Outcomes were compared against reference patients with VF who were unable or unwilling to undergo catheter ablation. The primary outcome was a composite of ICD shock, electrical storm, or all-cause mortality. Results - VF was induced and mapped in 6 patients (60±10 y, LVEF 46±19%) with ischemic (n=3) and nonischemic cardiomyopathy. An average of 3.3±0.5 sites of localized reentry during VF were targeted for radiofrequency ablation (38.3±10.9 minutes) during sinus rhythm, rendering VF non-inducible with pacing. Freedom from the primary outcome was 83% in the VF ablation group versus 17% in 6 non-ablation reference patients at a median of 1.0 years (IQR 0.5-1.5 years, p=0.046) follow-up. Conclusions - VESA is associated with a reduction in the combined endpoint compared with the non-ablation reference group. Additional work is required to understand the precise pathophysiologic changes which promote VF in order to improve preventative and therapeutic strategies.

    View details for DOI 10.1161/CIRCEP.120.008868

    View details for PubMedID 33550811

  • Arrhythmias Other Than Atrial Fibrillation in Those With an Irregular Pulse Detected With a Smartwatch: Findings From the Apple Heart Study. Circulation. Arrhythmia and electrophysiology Perino, A. C., Gummidipundi, S. E., Lee, J., Hedlin, H., Garcia, A., Ferris, T., Balasubramanian, V., Gardner, R. M., Cheung, L., Hung, G., Granger, C. B., Kowey, P., Rumsfeld, J. S., Russo, A. M., True Hills, M., Talati, N., Nag, D., Tsay, D., Desai, S., Desai, M., Mahaffey, K. W., Turakhia, M. P., Perez, M. V. 2021: CIRCEP121010063


    The Apple watch irregular pulse detection algorithm was found to have a positive predictive value of 0.84 for identification of atrial fibrillation (AF). We sought to describe the prevalence of arrhythmias other than AF in those with an irregular pulse detected on a smartwatch.The Apple Heart Study investigated a smartwatch-based irregular pulse notification algorithm to identify AF. For this secondary analysis, we analyzed participants who received an ambulatory ECG patch after index irregular pulse notification. We excluded participants with AF identified on ECG patch and described the prevalence of other arrhythmias on the remaining participant ECG patches. We also reported the proportion of participants self-reporting subsequent AF diagnosis.Among 419 297 participants enrolled in the Apple Heart Study, 450 participant ECG patches were analyzed, with no AF on 297 ECG patches (66%). Non-AF arrhythmias (excluding supraventricular tachycardias <30 beats and pauses <3 seconds) were detected in 119 participants (40.1%) with ECG patches without AF. The most common arrhythmias were frequent PACs (burden ≥1% to <5%, 15.8%; ≥5% to <15%, 8.8%), atrial tachycardia (≥30 beats, 5.4%), frequent PVCs (burden ≥1% to <5%, 6.1%; ≥5% to <15%, 2.7%), and nonsustained ventricular tachycardia (4-7 beats, 6.4%; ≥8 beats, 3.7%). Of 249 participants with no AF detected on ECG patch and patient-reported data available, 76 participants (30.5%) reported subsequent AF diagnosis.In participants with an irregular pulse notification on the Apple Watch and no AF observed on ECG patch, atrial and ventricular arrhythmias, mostly PACs and PVCs, were detected in 40% of participants. Defining optimal care for patients with detection of incidental arrhythmias other than AF is important as AF detection is further investigated, implemented, and refined.

    View details for DOI 10.1161/CIRCEP.121.010063

    View details for PubMedID 34565178

  • Role of 3.3fr Mapping Catheters in Defining and Ablating Mechanisms of Ventricular Arrhythmias: A Multicenter Experience Rogers, A. J., Greif, S., Perino, A. C., Shah, R. L., Viswanathan, M. N., Tholakanahalli, V. N., Singh, D., Badhwar, N. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Machine Learning of the Electrocardiogram to Detect Regional Structural Abnormalities of the Heart Rogers, A. J., Tooley, J., Thakkar, V., Torres, J., Xu, J., Bhatia, N. K., Tung, J., Alhusseini, M., Baykaner, T., Clifford, G., Zaharia, M., Ashley, E. A., Perez, M. V., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Deep Learning of Intracardiac Electrograms in Atrial Arrhythmia Rodrigo, M., Rogers, A. J., Ganesan, P., Alhusseini, M., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Sotalol-induced Wide Complex Rhythm: What is the Mechanism? Rogers, A. J., Wang, P. J., Badhwar, N. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Classification of Atrial Fibrillation by Deep Learning of Electrogram Shapes versus Rate and Regularity Rodrigo, M., Rogers, A. J., Ganesan, P., Alhusseini, M., Xu, J., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Islands of Organized 1:1 Conduction Within Atrial Fibrillation as Potential Targets for Ablation Ganesan, P., Bhatia, N. K., Rogers, A. J., Krummen, D. E., Alhusseini, M., Clopton, P., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2020
  • Machine Learned Cellular Phenotypes Predict Outcome in Ischemic Cardiomyopathy. Circulation research Rogers, A. J., Selvalingam, A., Alhusseini, M. I., Krummen, D. E., Corrado, C., Abuzaid, F., Baykaner, T., Meyer, C., Clopton, P., Giles, W. R., Bailis, P., Niederer, S. A., Wang, P. J., Rappel, W., Zaharia, M., Narayan, S. M. 2020


    RATIONALE: Susceptibility to ventricular arrhythmias (VT/VF) is difficult to predict in patients with ischemic cardiomyopathy either by clinical tools or by attempting to translate cellular mechanisms to the bedside.OBJECTIVE: To develop computational phenotypes of patients with ischemic cardiomyopathy, by training then interpreting machine learning (ML) of ventricular monophasic action potentials (MAPs) to reveal phenotypes that predict long-term outcomes.METHODS AND RESULTS: We recorded 5706 ventricular MAPs in 42 patients with coronary disease (CAD) and left ventricular ejection fraction (LVEF) {less than or equal to}40% during steady-state pacing. Patients were randomly allocated to independent training and testing cohorts in a 70:30 ratio, repeated K=10 fold. Support vector machines (SVM) and convolutional neural networks (CNN) were trained to 2 endpoints: (i) sustained VT/VF or (ii) mortality at 3 years. SVM provided superior classification. For patient-level predictions, we computed personalized MAP scores as the proportion of MAP beats predicting each endpoint. Patient-level predictions in independent test cohorts yielded c-statistics of 0.90 for sustained VT/VF (95% CI: 0.76-1.00) and 0.91 for mortality (95% CI: 0.83-1.00) and were the most significant multivariate predictors. Interpreting trained SVM revealed MAP morphologies that, using in silico modeling, revealed higher L-type calcium current or sodium calcium exchanger as predominant phenotypes for VT/VF.CONCLUSIONS: Machine learning of action potential recordings in patients revealed novel phenotypes for long-term outcomes in ischemic cardiomyopathy. Such computational phenotypes provide an approach which may reveal cellular mechanisms for clinical outcomes and could be applied to other conditions.

    View details for DOI 10.1161/CIRCRESAHA.120.317345

    View details for PubMedID 33167779

  • Comparing machine learning approaches to identify myocardial scar from the ECG Tung, J., Rogers, A. J., Ravi, N., Bhatia, N. K., Shah, R. L., Purewal, S. K., Baykaner, T., Rappel, W. J., Viswanathan, M. N., Brodt, C. R., Wang, P. J., Clifford, G., Tereshchenko, L., Narayan, S. M. OXFORD UNIV PRESS. 2020: 2048
  • Integration of novel monitoring devices with machine learning technology for scalable cardiovascular management. Nature reviews. Cardiology Krittanawong, C., Rogers, A. J., Johnson, K. W., Wang, Z., Turakhia, M. P., Halperin, J. L., Narayan, S. M. 2020


    Ambulatory monitoring is increasingly important for cardiovascular care but is often limited by the unpredictability of cardiovascular events, the intermittent nature of ambulatory monitors and the variable clinical significance of recorded data in patients. Technological advances in computing have led to the introduction of novel physiological biosignals that can increase the frequency at which abnormalities in cardiovascular parameters can be detected, making expert-level, automated diagnosis a reality. However, use of these biosignals for diagnosis also raises numerous concerns related to accuracy and actionability within clinical guidelines, in addition to medico-legal and ethical issues. Analytical methods such as machine learning can potentially increase the accuracy and improve the actionability of device-based diagnoses. Coupled with interoperability of data to widen access to all stakeholders, seamless connectivity (an internet of things) and maintenance of anonymity, this approach could ultimately facilitate near-real-time diagnosis and therapy. These tools are increasingly recognized by regulatory agencies and professional medical societies, but several technical and ethical issues remain. In this Review, we describe the current state of cardiovascular monitoring along the continuum from biosignal acquisition to the identification of novel biosensors and the development of analytical techniques and ultimately to regulatory and ethical issues. Furthermore, we outline new paradigms for cardiovascular monitoring.

    View details for DOI 10.1038/s41569-020-00445-9

    View details for PubMedID 33037325

  • Machine Learning to Classify Intracardiac Electrical Patterns during Atrial Fibrillation. Circulation. Arrhythmia and electrophysiology Alhusseini, M. I., Abuzaid, F., Rogers, A. J., Zaman, J. A., Baykaner, T., Clopton, P., Bailis, P., Zaharia, M., Wang, P. J., Rappel, W., Narayan, S. M. 2020


    Background - Advances in ablation for atrial fibrillation (AF) continue to be hindered by ambiguities in mapping, even between experts. We hypothesized that convolutional neural networks (CNN) may enable objective analysis of intracardiac activation in AF, which could be applied clinically if CNN classifications could also be explained. Methods - We performed panoramic recording of bi-atrial electrical signals in AF. We used the Hilbert-transform to produce 175,000 image grids in 35 patients, labeled for rotational activation by experts who showed consistency but with variability (kappa=0.79). In each patient, ablation terminated AF. A CNN was developed and trained on 100,000 AF image grids, validated on 25,000 grids, then tested on a separate 50,000 grids. Results - In the separate test cohort (50,000 grids), CNN reproducibly classified AF image grids into those with/without rotational sites with 95.0% accuracy (CI 94.8-95.2%). This accuracy exceeded that of support vector machines, traditional linear discriminant and k-nearest neighbor statistical analyses. To probe the CNN, we applied Gradient-weighted Class Activation Mapping which revealed that the decision logic closely mimicked rules used by experts (C-statistic 0.96). Conclusions - Convolutional neural networks improved the classification of intracardiac AF maps compared to other analyses, and agreed with expert evaluation. Novel explainability analyses revealed that the CNN operated using a decision logic similar to rules used by experts, even though these rules were not provided in training. We thus describe a scaleable platform for robust comparisons of complex AF data from multiple systems, which may provide immediate clinical utility to guide ablation.

    View details for DOI 10.1161/CIRCEP.119.008160

    View details for PubMedID 32631100

  • PREDICTING SUDDEN CARDIAC DEATH BY MACHINE LEARNING OF VENTRICULAR ACTION POTENTIALS Selvalingam, A., Alhusseini, M., Rogers, A. J., Krummen, D., Abuzaid, F. M., Baykaner, T., Clopton, P., Bailis, P., Zaharia, M., Wang, P., Narayan, S. ELSEVIER SCIENCE INC. 2020: 427
  • LARGER ORGANIZED AREAS IN PERSISTENT ATRIAL FIBRILLATION PREDICTS TERMINATION DURING ABLATION Ravi, N., Rogers, A. J., Bhatia, N., Tung, J. S., Krummen, D., Sauer, W., Alhusseini, M., Baykaner, T., Wang, P., Rappel, W., Narayan, S. ELSEVIER SCIENCE INC. 2020: 279
  • Non-invasive Spatial Mapping of Frequencies in Atrial Fibrillation: Correlation With Contact Mapping. Frontiers in physiology Rodrigo, M., Waddell, K., Magee, S., Rogers, A. J., Alhusseini, M., Hernandez-Romero, I., Costoya-Sánchez, A., Liberos, A., Narayan, S. M. 2020; 11: 611266


    Introduction: Regional differences in activation rates may contribute to the electrical substrates that maintain atrial fibrillation (AF), and estimating them non-invasively may help guide ablation or select anti-arrhythmic medications. We tested whether non-invasive assessment of regional AF rate accurately represents intracardiac recordings. Methods: In 47 patients with AF (27 persistent, age 63 ± 13 years) we performed 57-lead non-invasive Electrocardiographic Imaging (ECGI) in AF, simultaneously with 64-pole intracardiac signals of both atria. ECGI was reconstructed by Tikhonov regularization. We constructed personalized 3D AF rate distribution maps by Dominant Frequency (DF) analysis from intracardiac and non-invasive recordings. Results: Raw intracardiac and non-invasive DF differed substantially, by 0.54 Hz [0.13 - 1.37] across bi-atrial regions (R2 = 0.11). Filtering by high spectral organization reduced this difference to 0.10 Hz (cycle length difference of 1 - 11 ms) [0.03 - 0.42] for patient-level comparisons (R2 = 0.62), and 0.19 Hz [0.03 - 0.59] and 0.20 Hz [0.04 - 0.61] for median and highest DF, respectively. Non-invasive and highest DF predicted acute ablation success (p = 0.04). Conclusion: Non-invasive estimation of atrial activation rates is feasible and, when filtered by high spectral organization, provide a moderate estimate of intracardiac recording rates in AF. Non-invasive technology could be an effective tool to identify patients who may respond to AF ablation for personalized therapy.

    View details for DOI 10.3389/fphys.2020.611266

    View details for PubMedID 33584334

    View details for PubMedCentralID PMC7873897

  • The interconnected atrium: Acute impact of pulmonary vein isolation on remote atrial tissue. Journal of cardiovascular electrophysiology Rogers, A. J., Baykaner, T. n., Narayan, S. M. 2020

    View details for DOI 10.1111/jce.14389

    View details for PubMedID 32090385

  • Continuous Ablation Improves Lesion Maturation Compared with Intermittent Ablation Strategies. Journal of cardiovascular electrophysiology Rogers, A. J., Borne, R. T., Ho, G. n., Sauer, W. H., Wang, P. J., Narayan, S. M., Zheng, L. n., Nguyen, D. T. 2020


    Interrupted ablation is increasingly proposed as part of high-power short duration radiofrequency ablation (RFA) strategies and may also result from loss of contact from respiratory patterns or cardiac motion.To study the extent that ablation interruption affects lesions.In ex vivo and in vivo experiments, lesion characteristics and tissue temperatures were compared between continuous (Group 1) and interrupted (Groups 2,3) RFA with equal total ablation duration and contact force. Extended duration ablation lesions were also characterized from 1 to 5 minutes.In the ex vivo study, continuous RFA (Group 1) produced larger total lesion volumes compared with each interrupted ablation lesion group (273.8±36.5 mm3 vs. 205.1±34.2 and vs. 174.3±32.3, all p<0.001). Peak temperatures for Group 1 were higher at 3mm and 5mm than Groups 2 and 3. In vivo, continuous ablation resulted in larger lesions, greater lesion depths, and higher tissue temperatures. Longer ablation durations created larger lesion volumes and increased lesion depths. However, after 3 min of ablation, the rate of lesion volume and depth formation decreased.Continuous RFA delivery resulted in larger and deeper lesions with higher tissue temperatures compared to interrupted ablation. This work may have implications for high-power short duration ablation strategies, motivates strategies to reduce variations in ablation delivery, and provides an upper limit for ablation duration beyond which power delivery has diminishing returns. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/jce.14510

    View details for PubMedID 32323395

  • Non-Invasive Assessment of Complexity of Atrial Fibrillation: Correlation with Contact Mapping and Impact of Ablation. Circulation. Arrhythmia and electrophysiology Rodrigo, M. n., Climent, A. M., Hernández-Romero, I. n., Liberos, A. n., Baykaner, T. n., Rogers, A. J., Alhusseini, M. n., Wang, P. J., Fernández-Avilés, F. n., Guillem, M. S., Narayan, S. M., Atienza, F. n. 2020


    Background - It is difficult to non-invasively phenotype atrial fibrillation (AF) in a way that reflects clinical endpoints such as response to therapy. We set out to map electrical patterns of disorganization and regions of reentrant activity in AF from the body surface using electrocardiographic imaging (ECGI), calibrated to panoramic intracardiac recordings and referenced to AF termination by ablation. Methods - Bi-atrial intracardiac electrograms of 47 AF patients at ablation (30 persistent, 29 male, 63±9 years) were recorded with 64-pole basket catheters and simultaneous 57-lead body surface ECGs. Atrial epicardial electrical activity was reconstructed and organized sites were invasively and non-invasively tracked in 3D using phase singularity (PS). In a subset of 17 patients, sites of AF organization were targeted for ablation. Results - Body surface mapping showed greater AF organization near intracardially-detected drivers than elsewhere, both in PS density (2.3±2.1 vs 1.9±1.6, p=0.02) and number of drivers (3.2±2.3 vs 2.7±1.7, p=0.02). Complexity, defined as the number of stable AF reentrant sites, was concordant between non-invasive and invasive methods (r2 =0.5, CC=0.71). In the subset receiving targeted ablation, AF complexity showed lower values in those in whom AF terminated than those in whom AF did not terminate (p<0.01). Conclusions - AF complexity tracked non-invasively correlates well with organized and disorganized regions detected by panoramic intracardiac mapping, and correlates with the acute outcome by ablation. This approach may assist in bedside monitoring of therapy or in improving the efficacy of ongoing ablation procedures.

    View details for DOI 10.1161/CIRCEP.119.007700

    View details for PubMedID 32078374

  • Termination of persistent atrial fibrillation by ablating sites that control large atrial areas. 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 Bhatia, N. K., Rogers, A. J., Krummen, D. E., Hossainy, S. n., Sauer, W. n., Miller, J. M., Alhusseini, M. I., Peszek, A. n., Armenia, E. n., Baykaner, T. n., Brachmann, J. n., Turakhia, M. P., Clopton, P. n., Wang, P. J., Rappel, W. J., Narayan, S. M. 2020


    Persistent atrial fibrillation (AF) has been explained by multiple mechanisms which, while they conflict, all agree that more disorganized AF is more difficult to treat than organized AF. We hypothesized that persistent AF consists of interacting organized areas which may enlarge, shrink or coalesce, and that patients whose AF areas enlarge by ablation are more likely to respond to therapy.We mapped vectorial propagation in persistent AF using wavefront fields (WFF), constructed from raw unipolar electrograms at 64-pole basket catheters, during ablation until termination (Group 1, N = 20 patients) or cardioversion (Group 2, N = 20 patients). Wavefront field mapping of patients (age 61.1 ± 13.2 years, left atrium 47.1 ± 6.9 mm) at baseline showed 4.6 ± 1.0 organized areas, each separated by disorganization. Ablation of sites that led to termination controlled larger organized area than competing sites (44.1 ± 11.1% vs. 22.4 ± 7.0%, P < 0.001). In Group 1, ablation progressively enlarged unablated areas (rising from 32.2 ± 15.7% to 44.1 ± 11.1% of mapped atrium, P < 0.0001). In Group 2, organized areas did not enlarge but contracted during ablation (23.6 ± 6.3% to 15.2 ± 5.6%, P < 0.0001).Mapping wavefront vectors in persistent AF revealed competing organized areas. Ablation that progressively enlarged remaining areas was acutely successful, and sites where ablation terminated AF were surrounded by large organized areas. Patients in whom large organized areas did not emerge during ablation did not exhibit AF termination. Further studies should define how fibrillatory activity is organized within such areas and whether this approach can guide ablation.

    View details for DOI 10.1093/europace/euaa018

    View details for PubMedID 32243508

  • Letter in reply: Continuous radiofrequency ablation in scar-based arrhythmia substrate. Journal of cardiovascular electrophysiology Rogers, A. J., Nguyen, D. T. 2020

    View details for DOI 10.1111/jce.14534

    View details for PubMedID 32430949

  • Presence of Ablation of Atrial Organized Zones May Predict Response to Ablation Rogers, A. J., Bhatia, N. K., Alhusseini, M., Moosvi, N. F., Baykaner, T., Brodt, C., Clopton, P. L., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2019
  • Persistent Atrial Fibrillation as a Dynamic Network of Competing Zones of Control Bhatia, N. K., Rogers, A. J., Krummen, D. E., Alhusseini, M., Moosvi, N., Brodt, C., Baykaner, T., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2019
  • Developing Convolutional Neural Networks for Deep Learning of Ventricular Action Potentials to Predict Risk for Ventricular Arrhythmias Selvalingam, A., Alhusseini, M., Rogers, A. J., Krummen, D. E., Abuzaid, F. M., Zaman, J. A., Baykaner, T., Clopton, P. L., Bailis, P., Zaharia, M., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2019
  • Machine Learning of Remodeled Ventricular Action Potentials and Long-Term Follow-Up of Ventricular Arrhythmias Rogers, A. J., Alhusseini, M., Selvalingam, A., Krummen, D. E., Abuzaid, F., Zaman, J. A., Baykaner, T., Clopton, P., Bailis, P., Zaharia, M., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2019
  • Ablation of Sites That Control Large Areas During Atrial Fibrillation Cause Acute Termination Rogers, A. J., Bhatia, N. K., Alhusseini, M., Moosvi, N. F., Baykaner, T., Brodt, C., Clopton, P., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2019
  • Electrographic flow mapping in persistent atrial fibrillation Baykaner, T., Alhusseini, M., Rogers, A., Sauer, W., Ruppersberg, P., Narayan, S. WILEY. 2019: 1745–46
  • Wavefront Field Mapping Reveals a Physiologic Network Between Drivers Where Ablation Terminates Atrial Fibrillation. Circulation. Arrhythmia and electrophysiology Leef, G., Shenasa, F., Bhatia, N. K., Rogers, A. J., Sauer, W., Miller, J. M., Swerdlow, M., Tamboli, M., Alhusseini, M. I., Armenia, E., Baykaner, T., Brachmann, J., Turakhia, M. P., Atienza, F., Rappel, W., Wang, P. J., Narayan, S. M. 2019; 12 (8): e006835


    BACKGROUND: Localized drivers are proposed mechanisms for persistent atrial fibrillation (AF) from optical mapping of human atria and clinical studies of AF, yet are controversial because drivers fluctuate and ablating them may not terminate AF. We used wavefront field mapping to test the hypothesis that AF drivers, if concurrent, may interact to produce fluctuating areas of control to explain their appearance/disappearance and acute impact of ablation.METHODS: We recruited 54 patients from an international registry in whom persistent AF terminated by targeted ablation. Unipolar AF electrograms were analyzed from 64-pole baskets to reconstruct activation times, map propagation vectors each 20 ms, and create nonproprietary phase maps.RESULTS: Each patient (63.6±8.5 years, 29.6% women) showed 4.0±2.1 spatially anchored rotational or focal sites in AF in 3 patterns. First, a single (type I; n=7) or, second, paired chiral-antichiral (type II; n=5) rotational drivers controlled most of the atrial area. Ablation of 1 to 2 large drivers terminated all cases of types I or II AF. Third, interaction of 3 to 5 drivers (type III; n=42) with changing areas of control. Targeted ablation at driver centers terminated AF and required more ablation in types III versus I (P=0.02 in left atrium).CONCLUSIONS: Wavefront field mapping of persistent AF reveals a pathophysiologic network of a small number of spatially anchored rotational and focal sites, which interact, fluctuate, and control varying areas. Future work should define whether AF drivers that control larger atrial areas are attractive targets for ablation.

    View details for DOI 10.1161/CIRCEP.118.006835

    View details for PubMedID 31352796

  • Propagation velocity at atrial fibrillation sources: Go with the flow INTERNATIONAL JOURNAL OF CARDIOLOGY Rogers, A. J., Bhatia, N. K., Brodt, C. R., Narayan, S. M. 2019; 286: 76–77
  • Editorial: High density mapping of atrial fibrillation sources JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY Rogers, A. J., Bhatia, N. K., Brodt, C., Narayan, S. M. 2019; 30 (6): 964–65

    View details for DOI 10.1111/jce.13949

    View details for Web of Science ID 000472680300020

  • Comparing phase and electrographic flow mapping for persistent atrial fibrillation PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY Swerdlow, M., Tamboli, M., Alhusseini, M. I., Moosvi, N., Rogers, A. J., Leef, G., Wang, P. J., Rillig, A., Brachmann, J., Sauer, W. H., Ruppersberg, P., Narayan, S. M., Baykaner, T. 2019; 42 (5): 499–507

    View details for DOI 10.1111/pace.13649

    View details for Web of Science ID 000465228600002

  • Predictability in complex atrial arrhythmias: The N/N-1 algorithm to guide ablation of atrial tachycardias HEART RHYTHM Kaiser, D. W., Rogers, A. J., Narayan, S. M. 2019; 16 (4): 562–63
  • SITES THAT CONTROL LARGER AREAS DURING ATRIAL FIBRILLATION MAY DETERMINE TERMINATION DURING ABLATION Bhatia, N. K., Hossainy, S., Rogers, A., Alhusseini, M., Brodt, C., Moosvi, N., Baykaner, T., Wang, P., Rappel, W., Narayan, S. ELSEVIER SCIENCE INC. 2019: 400
  • MACHINE LEARNING IDENTIFIES SITES WHERE ABLATION TERMINATES PERSISTENT ATRIAL FIBRILLATION Alhusseini, M., Abuzaid, F., Clopton, P., Rogers, A., Rodrigo, M., Baykaner, T., Wang, P., Rappel, W., Narayan, S. ELSEVIER SCIENCE INC. 2019: 301
  • Structurally-based electrical predictors of atrial arrhythmias INTERNATIONAL JOURNAL OF CARDIOLOGY Rogers, A. J., Moosvi, N. F., Brodt, C. R., Narayan, S. M. 2019; 278: 151–52
  • Integrating blockchain technology with artificial intelligence for cardiovascular medicine. Nature reviews. Cardiology Krittanawong, C. n., Rogers, A. J., Aydar, M. n., Choi, E. n., Johnson, K. W., Wang, Z. n., Narayan, S. M. 2019

    View details for DOI 10.1038/s41569-019-0294-y

    View details for PubMedID 31605093

  • Large-Scale Assessment of a Smartwatch to Identify Atrial Fibrillation. The New England journal of medicine Perez, M. V., Mahaffey, K. W., Hedlin, H., Rumsfeld, J. S., Garcia, A., Ferris, T., Balasubramanian, V., Russo, A. M., Rajmane, A., Cheung, L., Hung, G., Lee, J., Kowey, P., Talati, N., Nag, D., Gummidipundi, S. E., Beatty, A., Hills, M. T., Desai, S., Granger, C. B., Desai, M., Turakhia, M. P., Apple Heart Study Investigators, Perez, M. V., Turakhia, M. P., Lhamo, K., Smith, S., Berdichesky, M., Sharma, B., Mahaffey, K., Parizo, J., Olivier, C., Nguyen, M., Tallapalli, S., Kaur, R., Gardner, R., Hung, G., Mitchell, D., Olson, G., Datta, S., Gerenrot, D., Wang, X., McCoy, P., Satpathy, B., Jacobsen, H., Makovey, D., Martin, A., Perino, A., O'Brien, C., Gupta, A., Toruno, C., Waydo, S., Brouse, C., Dorfman, D., Stein, J., Huang, J., Patel, M., Fleischer, S., Doll, E., O'Reilly, M., Dedoshka, K., Chou, M., Daniel, H., Crowley, M., Martin, C., Kirby, T., Brumand, M., McCrystale, K., Haggerty, M., Newberger, J., Keen, D., Antall, P., Holbrook, K., Braly, A., Noone, G., Leathers, B., Montrose, A., Kosowsky, J., Lewis, D., Finkelmeier, J. R., Bemis, K., Mahaffey, K. W., Desai, M., Talati, N., Nag, D., Rajmane, A., Desai, S., Caldbeck, D., Cheung, L., Granger, C., Rumsfeld, J., Kowey, P. R., Hills, M. T., Russo, A., Rockhold, F., Albert, C., Alonso, A., Wruck, L., Friday, K., Wheeler, M., Brodt, C., Park, S., Rogers, A., Jones, R., Ouyang, D., Chang, L., Yen, A., Dong, J., Mamic, P., Cheng, P., Shah, R., Lorvidhaya, P. 2019; 381 (20): 1909–17


    BACKGROUND: Optical sensors on wearable devices can detect irregular pulses. The ability of a smartwatch application (app) to identify atrial fibrillation during typical use is unknown.METHODS: Participants without atrial fibrillation (as reported by the participants themselves) used a smartphone (Apple iPhone) app to consent to monitoring. If a smartwatch-based irregular pulse notification algorithm identified possible atrial fibrillation, a telemedicine visit was initiated and an electrocardiography (ECG) patch was mailed to the participant, to be worn for up to 7 days. Surveys were administered 90 days after notification of the irregular pulse and at the end of the study. The main objectives were to estimate the proportion of notified participants with atrial fibrillation shown on an ECG patch and the positive predictive value of irregular pulse intervals with a targeted confidence interval width of 0.10.RESULTS: We recruited 419,297 participants over 8 months. Over a median of 117 days of monitoring, 2161 participants (0.52%) received notifications of irregular pulse. Among the 450 participants who returned ECG patches containing data that could be analyzed - which had been applied, on average, 13 days after notification - atrial fibrillation was present in 34% (97.5% confidence interval [CI], 29 to 39) overall and in 35% (97.5% CI, 27 to 43) of participants 65 years of age or older. Among participants who were notified of an irregular pulse, the positive predictive value was 0.84 (95% CI, 0.76 to 0.92) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular pulse notification and 0.71 (97.5% CI, 0.69 to 0.74) for observing atrial fibrillation on the ECG simultaneously with a subsequent irregular tachogram. Of 1376 notified participants who returned a 90-day survey, 57% contacted health care providers outside the study. There were no reports of serious app-related adverse events.CONCLUSIONS: The probability of receiving an irregular pulse notification was low. Among participants who received notification of an irregular pulse, 34% had atrial fibrillation on subsequent ECG patch readings and 84% of notifications were concordant with atrial fibrillation. This siteless (no on-site visits were required for the participants), pragmatic study design provides a foundation for large-scale pragmatic studies in which outcomes or adherence can be reliably assessed with user-owned devices. (Funded by Apple; Apple Heart Study number, NCT03335800.).

    View details for DOI 10.1056/NEJMoa1901183

    View details for PubMedID 31722151

  • Editorial: High density mapping of atrial fibrillation sources. Journal of cardiovascular electrophysiology Rogers, A. J., Bhatia, N. K., Brodt, C. n., Narayan, S. M. 2019

    View details for PubMedID 31056801

  • Online webinar training to analyse complex atrial fibrillation maps: A randomized trial. PloS one Mesquita, J. n., Maniar, N. n., Baykaner, T. n., Rogers, A. J., Swerdlow, M. n., Alhusseini, M. I., Shenasa, F. n., Brizido, C. n., Matos, D. n., Freitas, P. n., Santos, A. R., Rodrigues, G. n., Silva, C. n., Rodrigo, M. n., Dong, Y. n., Clopton, P. n., Ferreira, A. M., Narayan, S. M. 2019; 14 (7): e0217988


    Specific tools have been recently developed to map atrial fibrillation (AF) and help guide ablation. However, when used in clinical practice, panoramic AF maps generated from multipolar intracardiac electrograms have yielded conflicting results between centers, likely due to their complexity and steep learning curve, thus limiting the proper assessment of its clinical impact.The main purpose of this trial was to assess the impact of online training on the identification of AF driver sites where ablation terminated persistent AF, through a standardized training program. Extending this concept to mobile health was defined as a secondary objective.An online database of panoramic AF movies was generated from a multicenter registry of patients in whom targeted ablation terminated non-paroxysmal AF, using a freely available method (Kuklik et al-method A) and a commercial one (RhythmView-method B). Cardiology Fellows naive to AF mapping were enrolled and randomized to training vs no training (control). All participants evaluated an initial set of movies to identify sites of AF termination. Participants randomized to training evaluated a second set of movies in which they received feedback on their answers. Both groups re-evaluated the initial set to assess the impact of training. This concept was then migrated to a smartphone application (App).12 individuals (median age of 30 years (IQR 28-32), 6 females) read 480 AF maps. Baseline identification of AF termination sites by ablation was poor (40%±12% vs 42%±11%, P = 0.78), but similar for both mapping methods (P = 0.68). Training improved accuracy for both methods A (P = 0.001) and B (p = 0.012); whereas controls showed no change in accuracy (P = NS). The Smartphone App accessed AF maps from multiple systems on the cloud to recreate this training environment.Digital online training improved interpretation of panoramic AF maps in previously inexperienced clinicians. Combining online clinical data, smartphone apps and other digital resources provides a powerful, scalable approach for training in novel techniques in electrophysiology.

    View details for DOI 10.1371/journal.pone.0217988

    View details for PubMedID 31269029

  • Dielectric-Based Imaging And Navigation Of The Heart. Heart rhythm Rogers, A. J., Narayan, S. M. 2019

    View details for DOI 10.1016/j.hrthm.2019.07.016

    View details for PubMedID 31323349

  • Structurally-based electrical predictors of atrial arrhythmias. International journal of cardiology Rogers, A. J., Moosvi, N. F., Brodt, C. R., Narayan, S. M. 2018

    View details for PubMedID 30528625

  • Predictability in Complex Atrial Arrhythmias: the N/N-1 Algorithm to Guide Ablation of Atrial Tachycardias. Heart rhythm Kaiser, D. W., Rogers, A. J., Narayan, S. M. 2018

    View details for PubMedID 30465903

  • AF Drivers Where Ablation Terminates Persistent AF Fluctuate Due to Competing Drivers but Remain Anchored in Specific Locations Meckler, G. L., Kowalewski, C. A., Rogers, A. J., Rodrigo, M., Clopton, P., Shenasa, F., Alhusseini, M., Swerdlow, M., Joshi, V., Hossainy, S., Zaman, J., Baykaner, T., Brachmann, J., Miller, J., Krummen, D. E., Sauer, W., Viswanathan, M., Wang, P., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Electrode Density is Greater at Sites Where Ablation Acutely Terminates Atrial Fibrillation Rogers, A. J., Juan, R. C., Collart, O., Swerdlow, M., Alhusseini, M., Rodrigo, M., Kowalewski, C., Baykaner, T., Zaman, J., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Comparing Multiple Mapping Methods at Sites of AF Termination: The COMPARE-AF Registry. Zaman, J. A., Baykaner, T., Meckler, G., Clopton, P., Alhusseini, M., Shenasa, F., Kowalewski, C., Rogers, A., Vidmar, D., Krummen, D., Viswanathan, M., Rappel, W., Brachmann, J., Peters, N., Miller, J., Wang, P., Sauer, W., Atienza, F., Narayan, S. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Sites Where Ablation Terminated Atrial Fibrillation Identified by Machine Learning Models Alhusseini, M., Abuzaid, F., Swerdlow, M., Meckler, G., Clopton, P., Rogers, A., Rodrigo, M., Baykaner, T., Zaman, J., Kowalewski, C., Shenasa, F., Atienza, F., Mohan, N., Wang, P. J., Rappel, W. J., Bailis, P., Zaharia, M., Narayan, S. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Machine Learning Reveals That Drivers for Persistent Atrial Fibrillation at Termination Sites Show Irregular Rotational Cycles and Domain Size Alhusseini, M., Abuzaid, F., Swerdlow, M., Clopton, P., Meckler, G. L., Maniar, N. M., Rogers, A., Rodrigo, M., Baykaner, T., Zaman, J., Kowalewski, C., Shenasa, F., Tamboli, M., Viswanathan, M., Wang, P., Atienza, F., Rappel, W. J., Bailis, P., Zaharia, M., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Vector Propagation Automatically Identifies Sites of Termination of Persistent Atrial Fibrillation by Ablation Leef, G., Shenasa, F., Rogers, A. J., Baykaner, T., Atienza, F., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Procedural and Clinical Determinants of Acute Success of Driver Ablation for Persistent Atrial Fibrillation Baykaner, T., Rogers, A. J., Rodrigo, M., Alhusseini, M., Zaman, J. A., Wang, P. J., Narayan, S. M., Spitzer, S., Szili-Torok, T. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Localized Driver Regions That Control Larger Regions of the Atria May Be Critical to Sustaining Atrial Fibrillation: Analyses From Novel Vector Mapping Leef, G., Shenasa, F., Sauer, W., Miller, J. M., Vidmar, D., Swerdlow, M. A., Tomboli, M., Rogers, A. J., Alhusseini, M., Armenia, E., Baykaner, T., Brachmann, J., Atienza, F., Wang, P. J., Rappel, W., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2018
  • Integrating mapping methods for atrial fibrillation. Pacing and clinical electrophysiology : PACE Rogers, A. J., Tamboli, M., Narayan, S. M. 2018

    View details for DOI 10.1111/pace.13476

    View details for PubMedID 30144115

  • Interaction of Localized Drivers and Disorganized Activation in Persistent Atrial Fibrillation: Reconciling Putative Mechanisms Using Multiple Mapping Techniques CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Kowalewski, C. B., Shenasa, F., Rodrigo, M., Clopton, P., Meckler, G., Alhusseini, M. I., Swerdlow, M. A., Joshi, V., Hossainy, S., Zaman, J. B., Baykaner, T., Rogers, A. J., Brachmann, J., Miller, J. M., Krummen, D. E., Sauer, W. H., Peters, N. S., Wang, P. J., Narayan, S. M. 2018; 11 (6): e005846


    Mechanisms for persistent atrial fibrillation (AF) are unclear. We hypothesized that putative AF drivers and disorganized zones may interact dynamically over short time scales. We studied this interaction over prolonged durations, focusing on regions where ablation terminates persistent AF using 2 mapping methods.We recruited 55 patients with persistent AF in whom ablation terminated AF prior to pulmonary vein isolation from a multicenter registry. AF was mapped globally using electrograms for 360±45 cycles using (1) a published phase method and (2) a commercial activation/phase method.Patients were 62.2±9.7 years, 76% male. Sites of AF termination showed rotational/focal patterns by methods 1 and 2 (51/55 vs 55/55; P=0.13) in spatially conserved regions, yet fluctuated over time. Time points with no AF driver showed competing drivers elsewhere or disordered waves. Organized regions were detected for 61.6±23.9% and 70.6±20.6% of 1 minute per method (P=nonsignificant), confirmed by automatic phase tracking (P<0.05). To detect AF drivers with >90% sensitivity, 8 to 32 s of AF recordings were required depending on driver definition.Sites at which persistent AF terminated by ablation show organized activation that fluctuate over time, because of collision from concurrent organized zones or fibrillatory waves, yet recur in conserved spatial regions. Results were similar by 2 mapping methods. This network of competing mechanisms should be reconciled with existing disorganized or driver mechanisms for AF, to improve clinical mapping and ablation of persistent AF.URL: Unique identifier: NCT02997254.

    View details for PubMedID 29884620

  • Clinical Implications of Ablation of Drivers for Atrial Fibrillation A Systematic Review and Meta-Analysis CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Baykaner, T., Rogers, A. J., Meckler, G. L., Zaman, J., Navara, R., Rodrigo, M., Alhusseini, M., Kowalewski, C. B., Viswanathan, M. N., Narayan, S. M., Clopton, P., Wang, P. J., Heidenreich, P. A. 2018; 11 (5)
  • Independent mapping methods reveal rotational activation near pulmonary veins where atrial fibrillation terminates before pulmonary vein isolation JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY Navara, R., Leef, G., Shenasa, F., Kowalewski, C., Rogers, A. J., Meckler, G., Zaman, J. B., Baykaner, T., Park, S., Turakhia, M. P., Zei, P., Viswanathan, M., Wang, P. J., Narayan, S. M. 2018; 29 (5): 687–95

    View details for DOI 10.1111/jce.13446

    View details for Web of Science ID 000433580000005

  • Independent mapping methods reveal rotational activation near pulmonary veins where atrial fibrillation terminates before pulmonary vein isolation. Journal of cardiovascular electrophysiology Navara, R., Leef, G., Shenasa, F., Kowalewski, C., Rogers, A. J., Meckler, G., Zaman, J. A., Baykaner, T., Park, S., Turakhia, M. P., Zei, P., Viswanathan, M., Wang, P. J., Narayan, S. M. 2018


    OBJECTIVE: To investigate mechanisms by which atrial fibrillation (AF) may terminate during ablation near the pulmonary veins before the veins are isolated (PVI).INTRODUCTION: It remains unstudied how AF may terminate during ablation before PVs are isolated, or how patients with PV reconnection can be arrhythmia-free. We studied patients in whom PV antral ablation terminated AF before PVI, using two independent mapping methods.METHODS: We studied patients with AF referred for ablation, in whom biatrial contact basket electrograms were studied by both an activation/phase mapping method and by a second validated mapping method reported not to create false rotational activity.RESULTS: In 22 patients (age 60.1 ± 10.4, 36% persistent AF), ablation at sites near the PVs terminated AF (77% to sinus rhythm) prior to PVI. AF propagation revealed rotational (n=20) and focal (n=2) patterns at sites of termination by mapping method 1 and method 2. Both methods showed organized sites that were spatially concordant (P<0.001) with similar stability (P<0.001). Vagal slowing was not observed at sites of AF termination.DISCUSSION: PV antral regions where ablation terminated AF before PVI exhibited rotational and focal activation by two independent mapping methods. These data provide an alternative mechanism for the success of PVI, and may explain AF termination before PVI or lack of arrhythmias despite PV reconnection. Mapping such sites may enable targeted PV lesion sets and improved freedom from AF.

    View details for PubMedID 29377478

  • Clinical Implications of Ablation of Drivers for Atrial Fibrillation: A Systematic Review and Meta-Analysis. Circulation. Arrhythmia and electrophysiology Baykaner, T. n., Rogers, A. J., Meckler, G. L., Zaman, J. n., Navara, R. n., Rodrigo, M. n., Alhusseini, M. n., Kowalewski, C. A., Viswanathan, M. N., Narayan, S. M., Clopton, P. n., Wang, P. J., Heidenreich, P. A. 2018; 11 (5): e006119


    The outcomes from pulmonary vein isolation (PVI) for atrial fibrillation (AF) are suboptimal, but the benefits of additional lesion sets remain unproven. Recent studies propose ablation of AF drivers improves outcomes over PVI, yet with conflicting reports in the literature. We undertook a systematic literature review and meta-analysis to determine outcomes from ablation of AF drivers in addition to PVI or as a stand-alone procedure.Database search was done using the terms atrial fibrillation and ablation or catheter ablation and driver or rotor or focal impulse or FIRM (Focal Impulse and Rotor Modulation). We pooled data using random effects model and assessed heterogeneity with I2 statistic.Seventeen studies met inclusion criteria, in a cohort size of 3294 patients. Adding AF driver ablation to PVI reported freedom from AF of 72.5% (confidence interval [CI], 62.1%-81.8%; P<0.01) and from all arrhythmias of 57.8% (CI, 47.5%-67.7%; P<0.01). AF driver ablation when added to PVI or as stand-alone procedure compared with controls produced an odds ratio of 3.1 (CI, 1.3-7.7; P=0.02) for freedom from AF and an odds ratio of 1.8 (CI, 1.2-2.7; P<0.01) for freedom from all arrhythmias in 4 controlled studies. AF termination rate was 40.5% (CI, 30.6%-50.9%) and predicted favorable outcome from ablation(P<0.05).In controlled studies, the addition of AF driver ablation to PVI supports the possible benefit of a combined approach of AF driver ablation and PVI in improving single-procedure freedom from all arrhythmias. However, most studies are uncontrolled and are limited by substantial heterogeneity in outcomes. Large multicenter randomized trials are needed to precisely define the benefits of adding driver ablation to PVI.

    View details for PubMedID 29743170

  • Minimizing Radiation in the Modern Electrophysiology Laboratory. The Journal of innovations in cardiac rhythm management Rogers, A. J., Brodt, C. R. 2018; 9 (8): 3265–70


    Historically, the electrophysiology laboratory has relied heavily on the use of ionizing radiation in the form of fluoroscopy for a broad range of interventions and diagnostics. As the harmful effects of radiation have become increasingly recognized and procedural technologies have advanced, electrophysiologists have adopted new workflows. The purpose of this article is to review the available literature and experience in minimizing radiation in the modern electrophysiology laboratory. This review first covers general approaches to reducing fluoroscopy radiation in the electrophysiology suite, with concepts that apply across all procedure types. These include the reduction of infrared emission through fastidious fluoroscopy settings, new and proven solutions for radiation shielding, and methods of creating distance between the radiation source and the operator to reduce exposure. Following this discussion, we review specific task-based techniques for reducing radiation during special electrophysiologic procedures and workflows such as vascular access, coronary sinus lead placement, catheter manipulation, and periprocedural planning studies.

    View details for DOI 10.19102/icrm.2018.090805

    View details for PubMedID 32494501

    View details for PubMedCentralID PMC7252826

  • Minimizing Radiation in the Modern Electrophysiology Laboratory The Journal of Innovations in Cardiac Rhythm Management Rogers, A. J., Brodt, C. R. 2018; 2018 (9): 3265-3270
  • Rotational Drivers in Atrial Fibrillation: Are Multiple Techniques Circling Similar Mechanisms? Circulation. Arrhythmia and electrophysiology Zaman, J. A., Rogers, A. J., Narayan, S. M. 2017; 10 (12)

    View details for PubMedID 29254949

  • Rotational Drivers in Atrial Fibrillation Are Multiple Techniques Circling Similar Mechanisms? CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY Zaman, J. B., Rogers, A. J., Narayan, S. M. 2017; 10 (12)
  • Mechanisms for Persistent Atrial Fibrillation - Comparing Multiple Mapping Methods at Sites of Termination: The International COMPARE-AF Registry Baykaner, T., Zaman, J., AlHusseini, M., Vidmar, D., Meckler, G., Shenasa, F., Kowalewski, C., Rogers, A. J., Rodrigo, M., Krummen, D. E., Peters, N. S., Wang, P. J., Brachmann, J., Miller, J. M., Sauer, W. H., Rappel, W. J., Narayan, S. M. LIPPINCOTT WILLIAMS & WILKINS. 2017
  • Drivers of persistent atrial fibrillation: do focal or rotational regions differ in their stability over time? Navara, R., Leef, G., Shenasa, F., Meckler, G., Kowalewski, C., Baykaner, T., Alhusseini, M., Hossainy, S., Joshi, V., Rogers, A. J., Zaman, J., Park, S., Zei, P., Wang, P., Narayan, S. OXFORD UNIV PRESS. 2017: 638
  • Drivers of Persistent Atrial Fibrillation: Are Focal and Rotational Sites Transient or Stable Over Time? Navara, R., Leef, G., Shenasa, F., Kowalewski, C., Baykaner, T., Rogers, A., Zaman, J., Park, H., Zei, P., Wang, P. J., Narayan, S. M. WILEY. 2017: 606–7
  • Spatial relationship of sites for atrial fibrillation drivers and atrial tachycardia in patients with both arrhythmias. International journal of cardiology Baykaner, T. n., Zaman, J. A., Rogers, A. J., Navara, R. n., AlHusseini, M. n., Borne, R. T., Park, S. n., Wang, P. J., Krummen, D. E., Sauer, W. H., Narayan, S. M. 2017; 248: 188–95


    Atrial fibrillation (AF) often converts to and from atrial tachycardia (AT), but it is undefined if these rhythms are mechanistically related in such patients. We tested the hypothesis that critical sites for AT may be related to regional AF sources in patients with both rhythms, by mapping their locations and response to ablation on transitions to and from AF.From 219 patients undergoing spatial mapping of AF prior to ablation at 3 centers, we enrolled 26 patients in whom AF converted to AT by ablation (n=19) or spontaneously (n=7; left atrial size 42±6cm, 38% persistent AF). Both atria were mapped in both rhythms by 64-electrode baskets, traditional activation maps and entrainment.Each patient had a single mapped AT (17 reentrant, 9 focal) and 3.7±1.7 AF sources. The mapped AT spatially overlapped one AF source in 88% (23/26) of patients, in left (15/23) or right (8/23) atria. AF transitioned to AT by 3 mechanisms: (a) ablation anchoring AF rotor to AT (n=13); (b) residual, unablated AF source producing AT (n=6); (c) spontaneous slowing of AF rotor leaving reentrant AT at this site without any ablation (n=7). Electrogram analysis revealed a lower peak-to-peak voltage at overlapping sites (0.36±0.2mV vs 0.49±0.2mV p=0.03).Mechanisms responsible for AT and AF may arise in overlapping atrial regions. This mechanistic inter-relationship may reflect structural and/or functional properties in either atrium. Future work should delineate how acceleration of an organized AT may produce AF, and whether such regions can be targeted a priori to prevent AT recurrence post AF ablation.

    View details for PubMedID 28733070

  • Editorial commentary: What can lung transplantation teach us about the mechanisms of atrial arrhythmias? Trends in cardiovascular medicine Baykaner, T. n., Rogers, A. J., Zaman, J. A., Narayan, S. M. 2017

    View details for PubMedID 28893519

  • FMN fluorescence in inducible NOS constructs reveals a series of conformational states involved in the reductase catalytic cycle FEBS JOURNAL Ghosh, D. K., Ray, K., Rogers, A. J., Nahm, N. J., Salerno, J. C. 2012; 279 (7): 1306-1317


    Nitric oxide synthases (NOSs) produce NO as a molecular signal in the nervous and cardiovascular systems and as a cytotoxin in the immune response. NO production in the constitutive isoforms is controlled by calmodulin regulation of electron transfer. In the tethered shuttle model for NOS reductase function, the FMN domain moves between NADPH dehydrogenase and oxygenase catalytic centers. Crystal structures of neuronal NOS reductase domain and homologs correspond to an 'input state', with FMN in close contact with FAD. We recently produced two domain 'output state' (oxyFMN) constructs showing calmodulin dependent FMN domain association with the oxygenase domain. FMN fluorescence is sensitive to enzyme conformation and calmodulin binding. The inducible NOS (iNOS) oxyFMN construct is more fluorescent than iNOS holoenzyme. The difference in steady state fluorescence is rationalized by the observation of a series of characteristic states in the two constructs, which we assign to FMN in different environments. OxyFMN and holoenzyme share open conformations with an average lifetime of ~4.3 ns. The majority state in holoenzyme has a short lifetime of ~90 ps, probably because of FAD-FMN interactions. In oxyFMN about 25-30% of the FMN is in a state with a lifetime of 0.9 ns, which we attribute to quenching by heme in the output state. Occupancy of the output state together with our previous kinetic results yields a heme edge to FMN distance estimate of 12-15 Å. These results indicate that FMN fluorescence is a valuable tool to study conformational states involved in the NOS reductase catalytic cycle.

    View details for DOI 10.1111/j.1742-4658.2012.08525.x

    View details for Web of Science ID 000301571800015

    View details for PubMedID 22325715

  • A High-Fiber Diet Does Not Protect Against Asymptomatic Diverticulosis GASTROENTEROLOGY Peery, A. F., Barrett, P. R., Park, D., Rogers, A. J., Galanko, J. A., Martin, C. F., Sandler, R. S. 2012; 142 (2): 266-U158


    The complications of diverticulosis cause considerable morbidity in the United States; health care expenditures for this disorder are estimated to be $2.5 billion per year. Many physicians and patients believe that a high-fiber diet and frequent bowel movements prevent the development of diverticulosis. Evidence for these associations is poor. We sought to determine whether low-fiber or high-fat diets, diets that include large quantities of red meat, constipation, or physical inactivity increase risk for asymptomatic diverticulosis.We performed a cross-sectional study of 2104 participants, 30-80 years old, who underwent outpatient colonoscopy from 1998 to 2010. Diet and physical activity were assessed in interviews using validated instruments.The prevalence of diverticulosis increased with age, as expected. High intake of fiber did not reduce the prevalence of diverticulosis. Instead, the quartile with the highest fiber intake had a greater prevalence of diverticulosis than the lowest (prevalence ratio = 1.30; 95% confidence interval, 1.13-1.50). Risk increased when calculated based on intake of total fiber, fiber from grains, soluble fiber, and insoluble fiber. Constipation was not a risk factor. Compared to individuals with <7 bowel movements per week, individuals with >15 bowel movements per week had a 70% greater risk for diverticulosis (prevalence ratio = 1.70; 95% confidence interval, 1.24-2.34). Neither physical inactivity nor intake of fat or red meat was associated with diverticulosis.A high-fiber diet and increased frequency of bowel movements are associated with greater, rather than lower, prevalence of diverticulosis. Hypotheses regarding risk factors for asymptomatic diverticulosis should be reconsidered.

    View details for DOI 10.1053/j.gastro.2011.10.035

    View details for Web of Science ID 000299540000033

    View details for PubMedID 22062360

    View details for PubMedCentralID PMC3724216

  • Dietary Fiber is Not Associated With Diverticulosis Peery, A. F., Barrett, P. R., Park, D., Rogers, A. J., Locklear, T., Galanko, J. A., Martin, C. F., Sandler, R. S. W B SAUNDERS CO-ELSEVIER INC. 2011: S61
  • Simulation of Autonomous Robotic Multiple-Core Biopsy by 3D Ultrasound Guidance ULTRASONIC IMAGING Liang, K., Rogers, A. J., Light, E. D., von Allmen, D., Smith, S. W. 2010; 32 (2): 118-127


    An autonomous multiple-core biopsy system guided by real-time 3D ultrasound and operated by a robotic arm with 6+1 degrees of freedom has been developed. Using a specimen of turkey breast as a tissue phantom, our system was able to first autonomously locate the phantom in the image volume and then perform needle sticks in each of eight sectors in the phantom in a single session, with no human intervention required. Based on the fraction of eight sectors successfully sampled in an experiment of five trials, a success rate of 93% was recorded. This system could have relevance in clinical procedures that involve multiple needle-core sampling such as prostate or breast biopsy.

    View details for Web of Science ID 000280155300005

    View details for PubMedID 20687279

    View details for PubMedCentralID PMC3018680



    Feasibility studies of autonomous robot biopsies in tissue have been conducted using real-time three-dimensional (3-D) ultrasound combined with simple thresholding algorithms. The robot first autonomously processed 3-D image volumes received from the ultrasound scanner to locate a metal rod target embedded in turkey breast tissue simulating a calcification, and in a separate experiment, the center of a water-filled void in the breast tissue simulating a cyst. In both experiments the robot then directed a needle to the desired target, with no user input required. Separate needle-touch experiments performed by the image-guided robot in a water tank yielded an rms error of 1.15 mm. (E-mail:

    View details for DOI 10.1016/j.ultrasmedbio.2009.08.014

    View details for Web of Science ID 000278012200019

    View details for PubMedID 19900753

    View details for PubMedCentralID PMC2800959

  • 3-D Ultrasound Guidance of Autonomous Robot for Location of Ferrous Shrapnel IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL Rogers, A. J., Light, E. D., Smith, S. W. 2009; 56 (7): 1301-1303


    Vibrations can be induced in ferromagnetic shrapnel by a variable electromagnet. Real time 3-D color Doppler ultrasound located the induced motion in a needle fragment and determined its 3-D position in the scanner coordinates. This information was used to guide a robot which moved a probe to touch the shrapnel fragment.

    View details for DOI 10.1109/TUFFC.2009.1185

    View details for Web of Science ID 000267222400006

    View details for PubMedID 19574140

    View details for PubMedCentralID PMC2810201