Nitish Badhwar, MD is Professor of Medicine and Director of Cardiac Electrophysiology Training Program at Stanford University School of Medicine. Dr. Badhwar received his medical degree from Maulana Azad Medical College (University of Delhi, India). After completing his internal medicine training from New York Hospital of Queens (affiliated with Cornell Medical School), he worked as faculty in the Department of Medicine at Hospital of St. Raphael (Yale University School of Medicine). He completed Cardiac Electrophysiology training at UCSF with Dr. Scheinman. After being on faculty at UCSF for 15 years he recently joined the Arrhythmia Service at Stanford Hospital. He is a Fellow of American College of Cardiology and Heart Rhythm Society. He has been named best doctor in cardiac electrophysiology in San Francisco Magazine 3 years in a row (2015-2017). This is nominated by his peers. He was given Excellence in Teaching award in Medical Education by Academy of Medical Educators in 2015. He was an invited speaker at prestigious international meetings including Oriental Congress of Cardiology (OCC) in Shanghai, China; Cardiostim EHRA /Europace in Nice, France; Asia Pacific Heart Rhythm Society (APHRS) in Seoul, S Korea; American Heart Association Annual Scientific Session in New Orleans, LA and Indian Heart Rhythm Society in New Delhi, India.

Clinical Interest: Dr. Badhwar's clinical interest is in complex catheter ablation procedures including mapping and ventricular tachycardia (VT), atrial fibrillation (AF) and supraventricular tachycardia (SVT) including junctional variants of SVT. He started the epicardial ablation program at UCSF and also worked with Dr. Randall Lee to perform the first percutaneous epicardial left atrial appendage (LAA) ligation in the Bay Area in patients with atrial fibrillation. He has also differentiated himself in the field of electrophysiology by performing hybrid procedures with CT surgeons in patients with AF and VT. He is also involved in device implantation including pacemakers, ICD and biventricular pacing for heart failure.

Research Interest: Dr. Badhwar has published electrophysiologic characteristics of SVTs including atrial tachycardia arising from the coronary sinus musculature, para-hisian atrial tachycardia, left sided AVNRT, junctional tachycardia and nodofascicular tachycardia. He has also published on the use of nuclear medicine (ERNA) in assessing left ventricular dyssynchrony as well as optimal pacing sties in patients with heart failure requiring biventricular pacing. He has described the unique clinical characteristics of epicardial idiopathic VT arising from the cardiac crux. He has also published clinical outcomes of combining LAA ligation with catheter ablation of atrial fibrillation perform (first in human percutaneous closed chested Maze procedure) and is now part of a multi-center randomized study comparing standard ablation to ablation plus LAA ligation in patients with persistent atrial fibrillation (aMAZE trial).

Clinical Focus

  • Heart Rhythm Disorders
  • Clinical Cardiac Electrophysiology

Academic Appointments

Administrative Appointments

  • Director, Cardiac Electrophysiology Training Program, Stanford University School of Medicine (2018 - Present)

Professional Education

  • Board Certification: American Board of Internal Medicine, Cardiovascular Disease (2023)
  • Fellowship: UCSF Dept of Cardiology (2003) CA
  • Board Certification: American Board of Internal Medicine, Clinical Cardiac Electrophysiology (2003)
  • Fellowship: LSU Health Sciences Center - Shreveport (2001) LA
  • Residency: New York Hospital Queens (1996) NY
  • Medical Education: Maulana Azad Medical College (1993) India

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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  • aMAZE Study: LAA Ligation Adjunctive to PVI for Persistent or Longstanding Persistent Atrial Fibrillation Not Recruiting

    This study is a prospective, multicenter, randomized (2:1) controlled study to evaluate the safety and effectiveness of the LARIAT System to percutaneously isolate and ligate the Left Atrial Appendage from the left atrium as an adjunct to planned pulmonary vein isolation (PVI) catheter ablation in the treatment of subjects with symptomatic persistent or longstanding persistent atrial fibrillation. This study will be conducted in two stages: * Limited Early Stage (Stage 1): up to 250 subjects at up to 65 sites. (COMPLETED, transitioned to Stage 2) * Pivotal Stage/ Phase III (Stage 2): up to 600 subjects at up to 65 sites. (COMPLETED) All subjects from both stages will be included in the primary analysis.

    Stanford is currently not accepting patients for this trial. For more information, please contact Sarah Daadi, 650-498-5590.

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  • Pivotal Study Of A Dual Epicardial & Endocardial Procedure (DEEP) Approach Not Recruiting

    The objective of this study is to establish the safety and effectiveness of a dual epicardial and endocardial ablation procedure for patients presenting with Persistent Atrial Fibrillation or Longstanding Persistent Atrial Fibrillation

    Stanford is currently not accepting patients for this trial.

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Graduate and Fellowship Programs

  • Cardiac Electrophysiology (Fellowship Program)

All Publications

  • Phrenic Relocation by Endoscopy, Intentional Pneumothorax Using Carbon Dioxide, and Single Lung Ventilation (PHRENICS) Technique. JACC. Clinical electrophysiology Shah, R. L., Perino, A., Wang, P., Lee, A., Badhwar, N. 2023; 9 (5): 692-696


    Strategies to prevent right phrenic nerve (PN) injury during catheter ablation can be difficult to employ, ineffective, and risky. A novel PN-sparing technique involving single lung ventilation followed by "intentional pneumothorax" was prospectively evaluated in patients with multidrug refractory periphrenic atrial tachycardia (AT). This hybrid technique, termed PHRENICS (Phrenic Relocation by Endoscopy & Intentional Pneumothorax using Carbon Dioxide & Single Lung Ventilation), resulted in effective PN relocation away from the target site in all cases, allowing successful catheter ablation of AT without procedural complication or arrhythmia recurrence. The PHRENICS hybrid ablation technique can effectively mobilize the PN, avoiding unnecessary invasion of the pericardium, and can expand the safety of catheter ablation for periphrenic AT.

    View details for DOI 10.1016/j.jacep.2023.01.015

    View details for PubMedID 37225311

  • Sinus node sparing novel hybrid approach for treatment of inappropriate sinus tachycardia/postural sinus tachycardia: multicenter experience. Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing de Asmundis, C., Chierchia, G., Lakkireddy, D., Romeya, A., Okum, E., Gandhi, G., Sieira, J., Vloka, M., Jones, S. D., Shah, H., Winner, M., Patel, D., Whalen, S. P., Beaty, E. H., Kincaid, E. H., Lee, A., Brodt, C., Taylor, B. J., Colombowala, I., Romano, M., Morady, F., Stroker, E., Overeinder, I., Bala, G., Van Meeteren, J., Krauthammer, Y., Koerber, S., Shults, C., Thomaides, A., Badhwar, N., Gopinathannair, R., Shah, A., Tummala, R., Bello, D., Hoff, S., Almorad, A., Frazier, K., Brugada, P., La Meir, M. 2021


    BACKGROUND: The ideal treatment of inappropriate sinus tachycardia (IST) and postural orthostatic tachycardia syndrome (POTS) still needs to be defined. Medical treatments yield suboptimal results. Endocardial catheter ablation of the sinus node (SN) may risk phrenic nerve damage and open-heart surgery may be accompanied by unjustified invasive risks.METHODS: We describe our first multicenter experience of 255 consecutive patients (235 females, 25.94±3.84years) having undergone a novel SN sparing hybrid thoracoscopic ablation for drug-resistant IST (n=204, 80%) or POTS (n=51, 20%). As previously described, the SN was identified with 3D mapping. Surgery was performed through three 5-mm ports from the right side. A minimally invasive approach with a bipolar radiofrequency clamp was used to ablate targeted areas while sparing the SN region. The targeted areas included isolation of the superior and the inferior caval veins, and a crista terminalis line was made. All lines were interconnected.RESULTS: Normal sinus rhythm (SR) was restored in all patients at the end of the procedure. All patients discontinued medication during the follow-up. After a blanking period of 6months, all patients presented stable SR. At a mean of 4.07±1.8years, normal SN reduction and chronotropic response to exercise were present. In the 51 patients initially diagnosed with POTS, no syncope occurred. During follow-up, pericarditis was the most common complication (121 patients: 47%), with complete resolution in all cases. Pneumothorax was observed in 5 patients (1.9%), only 3 (1.1%) required surgical drainage. Five patients (1.9%) required a dual-chamber pacemaker due to sinus arrest>5s.CONCLUSIONS: Preliminary results of this multicenter experience with a novel SN sparing hybrid ablation of IST/POTS, using surgical thoracoscopic video-assisted epicardial ablation combined with simultaneous endocardial 3D mapping may prove to be an efficient and safe therapeutic option in patients with symptomatic drug-resistant IST and POTS. Importantly, in our study, all patients had a complete resolution of the symptoms and restored normal SN activity.

    View details for DOI 10.1007/s10840-021-01044-5

    View details for PubMedID 34424446

  • The Role of the Left Septal Fascicle in Fascicular Arrhythmias: Clinical Presentation and Laboratory Evaluation. JACC. Clinical electrophysiology Sanchez, J. M., Higuchi, S. n., Walters, T. E., Vedantham, V. n., Hsia, H. n., Gerstenfeld, E. P., Badhwar, N. n., Albona, M. n., Njeim, M. n., Scheinman, M. M. 2021


    This study describes a series of cases best explained by invoking the left septal fascicle (LSF) as a critical component of the arrhythmia circuit.Numerous anatomic studies have shown evidence of the LSF, but its precise role in the onset of arrhythmia is unclear.This paper presents 5 cases that implicated the LSF as a critical component of arrhythmogenesis.The first case had ventricular fibrillation repeatedly documented after a single premature atrial complex, produced left-sided conduction delay and simultaneous earliest activation of the left anterior fascicle (LAF) and left posterior fascicle (LPF). The LSF was ablated, resulting in an arrhythmia cure. The second case showed narrow QRS morphology during fascicular re-entrant tachycardia. The earliest mid-septal diastolic potentials had distal-to-proximal activation suggesting an LSF as a retrograde common pathway. The third case, with multiple ectopic Purkinje-related premature complexes exhibited earliest Purkinje potentials in the mid-septum, with subsequent anterograde activation of the LAF and LPF. Ablation of the LSF eliminated the premature ventricular complexes (PVCs). The fourth case demonstrated LPF and LAF PVCs. The His-left bundle activation showed earliest potentials at the proximal insertion of the left bundle during LPF PVCs, as well as a distal-to-proximal activation pattern during LAF PVC, suggestive of LSF involvement. The fifth case had focal non-re-entrant fascicular beats successfully ablated over the LSF.Involvement of the LSF is suspected with presentation of multiform fascicular and narrow QRS complex ventricular episodes of arrhythmia. Diagnoses and ablation require detailed mapping of the entire left sided conduction system.

    View details for DOI 10.1016/j.jacep.2020.12.012

    View details for PubMedID 33640350

  • Three Dimensional Transmural Mapping to Guide Ventricular Arrhythmia Ablation. Heart rhythm Narayan, S. M., Badhwar, N. n. 2021

    View details for DOI 10.1016/j.hrthm.2021.05.003

    View details for PubMedID 33964464

  • Open-Chest Ablation of Incessant Ventricular Tachycardia During Left Ventricular Assist Device Implantation. JACC. Clinical electrophysiology Shah, R. L., Hiesinger, W., Badhwar, N. 2020; 6 (7): 901–2

    View details for DOI 10.1016/j.jacep.2020.03.012

    View details for PubMedID 32703578

  • Long-term outcomes of ablation for ventricular arrhythmias in mitral valve prolapse. Journal of interventional cardiac electrophysiology : an international journal of arrhythmias and pacing Marano, P. J., Lim, L. J., Sanchez, J. M., Alvi, R., Nah, G., Badhwar, N., Gerstenfeld, E. P., Tseng, Z. H., Marcus, G. M., Delling, F. N. 2020


    Prior studies reporting efficacy of radiofrequency catheter ablation for complex ventricular ectopy in mitral valve prolapse (MVP) are limited by selective inclusion of bileaflet MVP, papillary muscle only ablation, or short-term follow-up. We sought to evaluate the long-term incidence of hemodynamically significant ventricular tachycardia (VT) or fibrillation (VF) in patients with MVP after initial ablation.We studied consecutive patients with MVP undergoing ablation for complex ventricular ectopy between 2013 and 2017 at our institution. Of 580 patients with MVP, we included 15 (2.6%, 10 women; mean age 50 ± 14 years, 53% bileaflet) with complex ventricular ectopy treated with initial ablation.Over a median follow-up of 3406 (1875-6551) days or 9 years, 5 of 15 (33%) patients developed hemodynamically significant VT/VF after their initial ablation and underwent placement of an implantable cardioverter defibrillator (ICD). Three of 5 also underwent repeat ablations. Sustained VT was inducible prior to index ablation in all 5 who developed VT/VF, compared to none of the 10 patients who did not develop VT/VF after index ablation (p = 0.002). Complex ventricular ectopy at index ablation was multifocal in all 5 patients who underwent repeat intervention versus 4 of 10 patients (40%) who did not (p = 0.04). All 3 patients with subsequent VT/VF who underwent repeat ablation had a new clinically dominant focus of ventricular arrhythmia and 3 of the patients with ICD had appropriate VT/VF therapies.In the long term, a subset of MVP patients treated with ablation for ventricular arrhythmias, all with multifocal ectopy on initial EP study, develop hemodynamically significant VT/VF. Our findings suggest the progressive nature of ventricular arrhythmias in patients with MVP and multifocal ectopy.

    View details for DOI 10.1007/s10840-020-00775-1

    View details for PubMedID 32506159

  • Approach to narrow complex tachycardia: non-invasive guide to interpretation and management. Heart (British Cardiac Society) Shah, R. L., Badhwar, N. 2020

    View details for DOI 10.1136/heartjnl-2019-315304

    View details for PubMedID 32303628

  • Long-term clinical outcomes from real-world experience of left atrial appendage exclusion with LARIAT device. Journal of cardiovascular electrophysiology Parikh, V., Bartus, K., Litwinowicz, R., Turagam, M. K., Sadowski, J., Kapelak, B., Bartus, M., Podolec, J., Brzezinski, M., Musat, D., Rasekh, A., Mittal, S., Cheng, J., Badhwar, N., Lee, R., Lakkireddy, D. 2019; 30 (12): 2849-2857


    Left atrial appendage closure (LAAC) with LARIAT has emerged as one of the alternatives to oral anticoagulation (OAC) in patients with nonvalvular atrial fibrillation (AF). Our aim was to study long-term outcomes in patients undergoing LARIAT procedure.We analyzed patients screened for LARIAT device in four centers between December 2009 and June 2012. Out of these, patients who didn't undergo LAAC with the LARIAT device due to unfavorable LAA morphology and other preprocedural contraindications were included in control group. We analyzed thromboembolism, bleeding events, and mortality between LAA and control group.About 153 patients were screened. Out of these, 108 (70.6%) patients underwent LARIAT placement (LAA arm) and 45 (29.4%) excluded patients were included in control arm. There were no differences in CHADS2 and CHA2 DS2 -VASc score. Mean HAS-BLED score was significantly higher in the LARIAT group (3.5 ± 1.06 vs 3.09 ± 1.22, P = .04). Mean follow-up time (in years) was 6.56 ± 0.84 in LAA and 6.5 ± 1.26 in control arm. During follow-up period, the LARIAT group was associated with significantly less thromboembolic events (1.9% vs 24%, P < .001), bleeding events (9.2% vs 24.4%, P = .03), and mortality (5.6% vs 20%, P = .01) as compared with the control group.Long-term data from routine clinical practice from our study suggests that LAA exclusion with LARIAT device is an effective treatment in management of nonvalvular AF patients with high risk of stroke, bleeding, and mortality. Further randomized trials, such as aMAZE, will provide more insight in this expanding field.

    View details for DOI 10.1111/jce.14229

    View details for PubMedID 31596044

  • Effect of Catheter Ablation vs Medical Therapy on Quality of Life Among Patients With Atrial Fibrillation The CABANA Randomized Clinical Trial JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Mark, D. B., Anstrom, K. J., Sheng, S., Piccini, J. P., Baloch, K. N., Monahan, K. H., Daniels, M. R., Bahnson, T. D., Poole, J. E., Rosenberg, Y., Lee, K. L., Packer, D. L., Robb, R. A., Rettmann, M. E., Martinez, B., Mascette, A., Jeffries, N., Mitchell, L., Flaker, G. G., Al-Khalidi, H. R., Silverstein, A., Ellis, A., Ussery, S. A., Moretz, K. L., Hagen, S., Anstrom, K., Baloch, K., Liu, D. M., Blount, J., Cowper, P., Knight, D., O'Neal, E. F., Holmes, D. R., Breen, J., Wilber, D., Reiffel, J., Kowey, P., Naccarelli, G., DiMarco, J. P., Davies, D., Cappato, R., Kalman, J. M., Kuck, K., Hindricks, G., Calkins, H., Stevenson, W. G., Buxton, A., Curtis, A. B., Davis, B. R., Ulrich, C. M., Lazzara, R., Peters, T., Bunch, J. T., Daubert, J., Halperin, B., Holshouser, J., Kutalek, S., Michaud, G., Mounsey, P., Wyse, G., Flaker, G., Bell, R., Greenspon, A., Logan, W., Sahota, P., Singh, N., Calkins, H., Schilling, R., Verma, A., Bahnson, T., DeVille, B., Monahan, K., DiMarco, J., Naccarelli, G., Gonzalez, M., Monahan, K., Poole, J., Patton, K., Prutkin, J., Johnson, G., Akoum, N., Auokar, P., Blatt, J., Birgersdotter-Green, U., Cha, Y., Mulpuru, S., Noseworthy, P., Chung, M., Gleva, M., Glotzer, T., Henrikson, C., Stecker, E., Kanjwal, Y., Kron, J., Kuriachan, V., Obel, O., Ranjan, R., Rho, R., Russo, A., Sullivan, R., Tzou, W., van der Zee, S., Serdoz, L., Wilson, M., Bowen, W., Pokushalov, E., Romanov, A., Meshalkin, E., Bunch, T., Bahnson, T., Noelker, G., Packer, D., Hindricks, G., Ardashev, A., Revishvili, A., Matsonashvili, G., Vijayaraman, P., Ince, H., Piorkowski, C., Neumann, T., Veenhuyzen, G., Gehi, A., Wilber, D., Sogade, F., Pappone, C., Berman, A., Shalaby, A., Kuck, K., Halperin, B., Tholakanahalli, V., Palma, E., Holshouser, J., Badhwar, N., Rashid, H., Cameron, C., Hummel, J., Saavedra, P., Deville, B., Chun, J., Roman-Gonzalez, J., Willems, S., Garan, H., Crespo, E., Cheung, P., Groenefeld, G., Schuger, C., Salam, T., Yang, Y., Pappone, C., Wichterle, D., Brachmann, J., Kautzner, J., Jayachandran, J., Kim, Y., Cole, C., Herweg, B., Lowe, M., Dougherty, A., Popov, S., Lowe, M., Spitzer, S., Bernstein, R., Simonson, J., Buch, E., Wu, S., Khan, M., Shinn, T., Neuzil, P., Mangrum, J., Calkins, H., Gonzalez, M., Mansour, M., Zabel, M., Kalman, J., Sanchez, J., Rothman, S., Bhandari, A., Tracy, C., Mitrani, R., Vorperian, V., Connelly, D., Wells, D., Ma, C., Verma, A., Robinson, M., Rubenstein, D., Vanoli, E., Zhang, S., Cummings, J., Viswanathan, M., Monir, G., Marchlinski, F., Franklin, J., Koplan, B., Sanders, P., Rashba, E., Gallagher, M., Gonska, B., Chen, M., Leong-Sit, P., Zimmerman, J., Pezeshkian, N., Cohen, A., Kalvaitis, S., Davies, D., Borggrefe, M., Pak, H., Russo, A., Henrikson, C., Greer, G., Coromilas, J., Khairallah, F., Sosa-Suarez, G., Lindsay, B., Fisher, W., Bailin, S., Tran, A., Starek, Z., Preminger, M., Sheppard, R., Costea, A., Ellenbogen, K., Arentz, T., De Ponti, R., Aleong, R., Colley, B., Baig, K., Krishnan, K., Menon, S., Simmons, T., Bruce, G., Chinitz, L., Natale, A., Cappato, R., CABANA Investigators, CABANA Rhythm Monitoring, Clinical Site Principal Investigat 2019; 321 (13): 1275–85


    Catheter ablation is more effective than drug therapy in restoring sinus rhythm in patients with atrial fibrillation (AF), but its incremental effect on long-term quality of life (QOL) is uncertain.To determine whether catheter ablation is more beneficial than conventional drug therapy for improving QOL in patients with AF.An open-label randomized clinical trial of catheter ablation vs drug therapy in 2204 symptomatic patients with AF older than 65 years or 65 years or younger with at least 1 risk factor for stroke. Patients were enrolled from November 2009 to April 2016 from 126 centers in 10 countries. Follow-up ended in December 2017.Pulmonary vein isolation, with additional ablation procedures at the discretion of the investigators, for the catheter ablation group (n = 1108) and standard rhythm and/or rate-control drugs selected and managed by investigators for the drug therapy group (n = 1096).Prespecified co-primary QOL end points at 12 months, including the Atrial Fibrillation Effect on Quality of Life (AFEQT) summary score (range, 0-100; 0 indicates complete disability and 100 indicates no disability; patient-level clinically important difference, ≥5 points) and the Mayo AF-Specific Symptom Inventory (MAFSI) frequency score (range, 0-40; 0 indicates no symptoms and 40 indicates the most severe symptoms; patient-level clinically important difference, ≤-1.6 points) and severity score (range, 0-30; 0 indicates no symptoms and 30 indicates the most severe symptoms; patient-level clinically important difference, ≤-1.3 points).Among 2204 randomized patients (median age, 68 years; 1385 patients [63%] were men, 946 [43%] had paroxysmal AF, and 1256 [57%] had persistent AF), the median follow-up was 48.5 months, and 1968 (89%) completed the trial. The mean AFEQT summary score was more favorable in the catheter ablation group than the drug therapy group at 12 months (86.4 points vs 80.9 points) (adjusted difference, 5.3 points [95% CI, 3.7-6.9]; P < .001). The mean MAFSI frequency score was more favorable for the catheter ablation group than the drug therapy group at 12 months (6.4 points vs 8.1 points) (adjusted difference, -1.7 points [95% CI, -2.3 to -1.2]; P < .001) and the mean MAFSI severity score was more favorable for the catheter ablation group than the drug therapy group at 12 months (5.0 points vs 6.5 points) (adjusted difference, -1.5 points [95% CI, -2.0 to -1.1]; P < .001).Among patients with symptomatic atrial fibrillation, catheter ablation, compared with medical therapy, led to clinically important and significant improvements in quality of life at 12 months. These findings can help guide decisions regarding management of atrial Identifier: NCT00911508.

    View details for DOI 10.1001/jama.2019.0692

    View details for Web of Science ID 000463076800014

    View details for PubMedID 30874716

  • Hybrid and surgical procedures for the treatment of persistent and longstanding persistent atrial fibrillation. Expert review of cardiovascular therapy Sanchez, J. M., Al-Dosari, G., Chu, S., Beygui, R., Deuse, T., Badhwar, N., Lee, R. J. 2018; 16 (2): 91-97


    Atrial fibrillation (AF) is the most common cardiac arrhythmia. The incidence of AF increases with age and is associated with increased stroke, heart failure and mortality. Persistent and long standing persistent AF is difficult to treat and often refractory to medical therapy and catheter ablation. Areas covered: This article reviews the historical development of the surgical Cox-MAZE procedure and current hybrid and minimally invasive surgical approaches for the treatment of persistent and long standing persistent AF. The role of concomitant pulmonary vein isolation and left atrial appendage (LAA) exclusion will also be reviewed. Expert commentary: An ablation pattern emulating the Cox-Maze surgical procedure is commonly needed to obtain maintenance of sinus rhythm in patients with persistent and long standing persistent atrial fibrillation. Minimally invasive bilateral thorascopic surgical procedures can achieve a similar Cox-Maze lesion set, but are associated with increased adverse events compared to catheter ablation. Future prospective randomized studies are required to confirm whether the recently developed hybrid subxyphoid epicardial/endocardial procedure and percutaneous LAA ligation and catheter ablation are indeed as effective as surgical options with less adverse events.

    View details for DOI 10.1080/14779072.2018.1425140

    View details for PubMedID 29327638

  • Arrhythmias including Atrial Fibrillation and Congenital Heart Disease in Kleefstra Syndrome: a possible epigenetic link. 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 Vasireddi, S. K., Draksler, T. Z., Bouman, A., Kummeling, J., Wheeler, M., Reuter, C., Srivastava, S., Harris, J., Fisher, P. G., Narayan, S. M., Wang, P. J., Badhwar, N., Kleefstra, T., Perez, M. V. 2024


    BACKGROUND: Kleefstra syndrome (KS), often diagnosed in early childhood, is a rare genetic disorder due to haploinsufficiency of EHMT1 and is characterized by neuromuscular and intellectual developmental abnormalities. Although congenital heart disease (CHD) is common, the prevalence of arrhythmias and CHD subtypes in KS is unknown.METHODS: Inspired by a novel case series of KS patients with atrial tachyarrhythmias in the USA, we evaluate the two largest known KS registries for arrhythmias and CHD: Radboudumc (50 patients) based on health record review at Radboud University Medical Center in the Netherlands, and GenIDA (163 patients) based on world-wide surveys of patient families.RESULTS: Three KS patients (aged 17-25 years) presented with atrial tachyarrhythmias without manifest CHD. In the international KS registries, the median(IQR) age was considerably younger; GenIDA/Radboudumc at 10/13.5 (12/13) years respectively. Both registries had a 40% prevalence of cardiovascular abnormalities, the majority being CHD, including septal defects, vascular malformations, and valvular disease. Interestingly, 4 (8%) patients in the Radboudumc registry reported arrhythmias without CHD, including one AF, two with supraventricular tachycardias (SVTs), and one with non-sustained ventricular tachycardia. The GenIDA registry reported one patient with AF and another with chronic ectopic atrial tachycardia. In total, atrial tachyarrhythmias were noted in six young KS patients (6/213 or 3%) with at least four (3 AF and 1 AT) without structural heart disease.CONCLUSION: In addition to a high prevalence of CHD, evolving data reveals early-onset atrial tachyarrhythmias in young KS patients, including AF, even in the absence of structural heart disease.

    View details for DOI 10.1093/europace/euae003

    View details for PubMedID 38195854

  • Mechanically induced electrical storm as a complication of cardiac resynchronization therapy: A case report. Indian pacing and electrophysiology journal Feng, Z., Marcus, G. M., Badhwar, N. 2023


    BACKGROUND: Cardiac resynchronization therapy (CRT) has been shown to improve both the functional status and mortality of heart failure patients with left bundle branch block. Multiple recent studies suggest several mechanisms for proarrhythmia associated with CRT device.CASE SUMMARY: A 51-year-old male with symptomatic non-ischemic cardiomyopathy and no previous history of ventricular arrhythmias underwent placement of a biventricular cardioverter-defibrillator. The patient developed sustained monomorphic ventricular tachycardia (VT) soon after implantation. The VT recurred despite reprogramming to right ventricular only pacing. The electrical storm resolved only after a subsequent discharge from the defibrillator caused inadvertent dislodgement of the coronary sinus lead. No recurrent VT occurred throughout 10-years follow up after urgent coronary sinus lead revision.DISCUSSION: We describe the first reported case of mechanically induced electrical storm due to the physical presence of the CS lead in a patient with a new CRT-D device. It is important to recognize mechanical proarrhythmia as a potential mechanism of electrical storm, as it may be intractable to device reprogramming. Urgent coronary sinus lead revision should be considered. Further studies on this mechanism of proarrhythmia are needed.

    View details for DOI 10.1016/j.ipej.2023.05.001

    View details for PubMedID 37196771

  • Ambient Circulation Surrounding an Ablation Catheter Tip Affects Ablation Lesion Characteristics. Journal of cardiovascular electrophysiology Nussinovitch, U., Wang, P., Babakhanian, M., Narayan, S. M., Viswanathan, M., Badhwar, N., Zheng, L., Sauer, W. H., Nguyen, D. T. 2023


    The association between ambient circulating environments (CE) and ablation lesions has been largely underexplored.Viable bovine myocardium was placed in a saline bath in an ex vivo endocardial model. RF ablation was performed using 3 different ablation catheters: 3.5mm open irrigated (OI), 4 mm, and 8 mm. Variable flow rates of surrounding bath fluids were applied to simulate standard flow, high flow, and no flow. For in-vivo epicardial ablation, 24 rats underwent a single OI ablation and performed with circulating saline (30 ml/min; n=12), vs. those immersed in saline without circulation (n=12).High flow reduced ablation lesion volumes for all 3 catheters. In no flow endocardial CE, both 4 mm and OI catheters produced smaller lesions compared to standard flow. However, the 8 mm catheter produced the largest lesions in a no flow CE. Ablation performed in an in-vivo model with CE resulted in smaller lesions compared to ablation performed in a no-flow environment. No statistically significant differences in steam pops were found amongst the groups.A higher endocardial CE flow can decrease RF effectiveness. Cardiac tissue subjected to no endocardial CE flow may also limit RF for 4 mm catheters, but not for OI catheters; these findings may have implications for RF ablation safety and efficacy, especially, in the epicardial space without circulating fluid or in the endocardium under varying flow conditions. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/jce.15874

    View details for PubMedID 36852908

  • 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


    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

  • Needle-Tipped Catheter Ablation of Papillary Muscle Results in Deeper and Larger Ablation Lesions. Journal of cardiovascular translational research Nussinovitch, U., Wang, P., Babakhanian, M., Narayan, S. M., Viswanathan, M., Badhwar, N., Zheng, L., Sauer, W. H., Nguyen, D. T. 2022


    Ventricular tachycardia associated with papillary muscle (PM) is often refractory to standard radiofrequency ablation (RFA). The needle-tipped ablation catheter (NT-AC) has been used to treat deep intramyocardial substrates, but its use for PM has not been characterized. Using an ex vivo experimental platform, both 3mm and 6mm NT-AC created larger ablation lesion volumes and depths than open-irrigated ablation catheter did (OI-AC; e.g., 57.12±9.70mm3 and 2.42±0.22mm, respectively; p<0.01 for all comparisons). Longer NT-AC extension (6mm) resulted in greater ablation lesion volumes and maximum depths (e.g., 333.14±29.13mm3 and 6.46±0.29mm, respectively, compared to the shorter 3mm NT-AC extension, 143.33±12.77mm3, and 4.46±0.14mm; both p<0.001). There were no steam pops. In conclusion, for PM ablation, the NT-AC was able to achieve ablation lesions that were larger and deeper than with conventional OI-AC. Ablation of PM may be another application for needle-tip ablation. Further studies are warranted to establish long-term safety and efficacy in human studies.

    View details for DOI 10.1007/s12265-022-10331-z

    View details for PubMedID 36264437

  • 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

  • Perpendicular Catheter Orientation During Papillary Muscle Ablation Results in Larger, Deeper Lesions. Journal of cardiovascular electrophysiology Nussinovitch, U., Wang, P., Narayan, S., Viswanathan, M., Badhwar, N., Zheng, L., Sauer, W. H., Nguyen, D. T. 2022


    INTRODUCTION: Ablation of papillary muscles (PM) for refractory ventricular arrhythmias can often be challenging. The catheter approach and orientation during ablation may affect optimal radiofrequency (RF) delivery. Yet, no previous study investigated the association between catheter orientation and PM lesion size. We evaluated ablation lesion characteristics with various catheter orientations relative to the PM tissue during open irrigated ablation, using a standardized, experimental setting.METHODS: Viable bovine PM was positioned on a load cell in a circulating saline bath. RF ablation was performed over PM tissue at 50W, with the open irrigated catheter positioned either perpendicular or parallel to the PM surface. Applied force was 10 grams. Ablation lesions were sectioned and underwent quantitative morphometric analysis.RESULTS: A catheter position oriented directly perpendicular to the PM tissue resulted in the largest ablation lesion volumes and depths compared to ablation with the catheter parallel to PM tissue (75.26±8.40 mm3 vs. 34.04±2.91 mm3 , p<0.001) and (3.33±0.18 mm vs. 2.24±0.10 mm, p<0.001), respectively. There were no significant differences in initial impedance, peak voltage, peak current, or overall decrease in impedance among groups. Parallel catheter orientation resulted in higher peak temperature (41.33±0.28°C vs. 40.28±0.24°C, p=0.003), yet, there were no steam pops in either group.CONCLUSION: For PM ablation, catheter orientation perpendicular to the PM tissue achieves more effective and larger ablation lesions, with greater lesion depth. This may have implications for the chosen ventricular access approach, the type of catheter used, consideration for remote navigation, and steerable sheaths. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/jce.15408

    View details for PubMedID 35133050

  • 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

  • Importance of the Activation Sequence of the His or Right Bundle for Diagnosis of Complex Tachycardia Circuits. Circulation. Arrhythmia and electrophysiology Viswanathan, M. N., Julie He, B., Sung, R., Hoffmayer, K. S., Badhwar, N., Lee, A., Goldberger, J. J., Hsia, H. H., Jackman, W. M., Scheinman, M. M. 2021: CIRCEP120009194


    In this review, we emphasize the unique value of recording the activation sequence of the His bundle or right bundle branch (RB) for diagnoses of various supraventricular and fascicular tachycardias. A close analysis of the His to RB (H-RB) activation sequence can help differentiate various forms of supraventricular tachycardias, namely atrioventricular nodal reentry tachycardia from concealed nodofascicular tachycardia, a common clinical dilemma. Furthermore, bundle branch reentry tachycardia and fascicular tachycardias often are included in the differential diagnosis of supraventricular tachycardia with aberrancy, and the use of this technique can help the operator make the distinction between supraventricular tachycardias and these other forms of ventricular tachycardias using the His-Purkinje system. We show that this technique is enhanced by the use of multipolar catheters placed to span the proximal His to RB position to record the activation sequence between proximal His potential to the distal RB potential. This allows the operator to fully analyze the activation sequence in sinus rhythm as compared to that during tachycardia and may help target ablation of these arrhythmias. We argue that 3 patterns of H-RB activation are commonly identified-the anterograde H-RB pattern, the retrograde H-RB (right bundle to His bundle) pattern, and the chevron H-RB pattern (simultaneous proximal His and proximal RB activation)-and specific arrhythmias tend to be associated with specific H-RB activation sequences. We show that being able to record and categorize this H-RB relationship can be instrumental to the operator, along with standard pacing maneuvers, to make an arrhythmia diagnosis in complex tachycardia circuits. We highlight the importance of H-RB activation patterns in these complex tachycardias by means of case illustrations from our groups as well as from prior reports.

    View details for DOI 10.1161/CIRCEP.120.009194

    View details for PubMedID 34601885

  • Substrate Characterization and Outcomes of Ventricular Tachycardia Ablation in Titin Cardiomyopathy: A Multicenter Study. Circulation. Arrhythmia and electrophysiology Enriquez, A., Liang, J., Smietana, J., Muser, D., Salazar, P., Shah, R., Badhwar, N., Bogun, F., Marchlinski, F. E., Garcia, F., Baranchuk, A., Tung, R., Redfearn, D., Santangeli, P. 2021


    Background - Truncating variants of the titin gene (TTNtv) are a leading cause of dilated cardiomyopathy (DCM) and have been associated with an increased risk of ventricular arrhythmias. This study evaluated the substrate distribution and the acute and long-term outcomes of patients with TTN-related cardiomyopathy undergoing ventricular tachycardia (VT) ablation. Methods - This multicenter registry included 15 patients with DCM (age 59±11 years, 93% male, ejection fraction 30±12%) and genotypically confirmed TTNtvs who underwent VT ablation between July 2014 and July 2020. Results - All patients presented with sustained monomorphic VT, including electrical storm in 4 of them. A median of 2 VTs per patient were induced during the procedure (cycle-length 318±68 ms) and the predominant morphologies were left bundle branch block with inferior axis (39%) and right bundle branch block with inferior axis (29%). A complete map of the left ventricle (LV) was created in 12 patients and showed voltage abnormalities mainly at the periaortic (92%) and basal septal region (58%). A preprocedural cardiac magnetic resonance imaging was available in 13 patients and in 11 there was evidence of LV delayed gadolinium enhancement, with predominantly midmyocardial distribution. Sequential ablation from both sides of the septum was required in 47% of patients to target septal intramural substrate and epicardial ablation was performed in 20%. At the end of the procedure, the clinical VT was noninducible in all patients, while in 3 cases a non-clinical VT was still inducible. After a follow-up of 26.5±23.0 months, 53% of patients experienced VT recurrence, 20% received transplant or mechanical circulatory support and 7% died. Conclusion - The arrhythmogenic substrate in TTN-related cardiomyopathy involves the basal septal and perivalvular regions. Long-term outcomes of catheter ablation are modest, with high recurrence rate, likely related to an intramural location of VT circuits.

    View details for DOI 10.1161/CIRCEP.121.010006

    View details for PubMedID 34315225

  • Generation of three heterozygous KCNH2 mutation-carrying human induced pluripotent stem cell lines for modeling LQT2 syndrome. Stem cell research Mondejar-Parreno, G., Jahng, J. W., Belbachir, N., Wu, B. C., Zhang, X., Perez, M. V., Badhwar, N., Wu, J. C. 2021; 54: 102402


    Congenital long QT syndrome type 2 (LQT2) results from KCNH2 mutations that cause loss of Kv11.1 channel function which can lead to arrhythmias, syncope, and sudden death. Here, we generated three human-induced pluripotent stem cell (iPSC) lines from peripheral blood mononuclear cells (PBMCs) of two LQT2 patients carrying pathogenic variants (c.1714G>A and c.2960del) and one LQT2 patient carrying a variant of uncertain significance (c.1870A>T) in KCNH2. All lines show typical iPSC morphology, high expression of pluripotent markers, normal karyotype, and differentiate into three germ layers in vitro. These lines are valuable resources for studying the pathological mechanisms of LQTS caused by caused by KCNH2 mutations.

    View details for DOI 10.1016/j.scr.2021.102402

    View details for PubMedID 34051449

  • 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


    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

  • Deformation of stylet-driven leads & helix unraveling during acute explant after conduction system pacing. Indian pacing and electrophysiology journal Shah, R. L., Kapoor, R., Badhwar, N. 2021

    View details for DOI 10.1016/j.ipej.2021.06.001

    View details for PubMedID 34118434

  • Supraventricular tachycardia with shifting atrial activation patterns caused by extrastimuli: What is the mechanism? Journal of cardiovascular electrophysiology Chandh Raja, D., Nair, K. K., Badhwar, N., Pandurangi, U. M. 2020


    A 45-year old female presented with recurrent symptomatic palpitations responsive to adenosine. An electrophysiology study was performed with decapolar catheter in the coronary sinus (CS) and quadripolar catheters in the His and right ventricular (RV) apex. This article is protected by copyright. All rights reserved.

    View details for DOI 10.1111/jce.14669

    View details for PubMedID 32656885

  • Ablation of Supraventricular Tachycardias From Concealed Left-sided Nodoventricular And Nodofascicular Accessory Pathways. Circulation. Arrhythmia and electrophysiology Cardona-Guarache, R., Han, F. T., Nguyen, D. T., Chicos, A. B., Badhwar, N., Knight, B. P., Johnson, C. J., Heaven, D., Scheinman, M. M. 2020


    Background - Nodoventricular (NV) and nodofascicular (NF) accessory pathways (AP) are uncommon connections between the AV node and the fascicles or ventricles. Methods - Five patients with NF or NV tachycardia were studied. Results - We identified 5 patients with concealed, left-sided NV (n=4) and NF (n=1) AP. We proved the participation of AP in tachycardia by delivering His-synchronous PVCs that either delayed the subsequent atrial electrogram or terminated the tachycardia (n=3), and by observing an increase in VA interval coincident with left bundle branch block (LBBB) (n=2). The APs were not atrioventricular pathways because the septal VA interval during tachycardia was <70ms in 3, 1 had spontaneous AV dissociation, and in 1 the atria were dissociated from the circuit with atrial overdrive pacing. Entrainment from the right ventricle showed ventricular fusion in 4 out of 5 cases. A left-sided origin of the AP was suspected after failed ablation of the right inferior extension of AV node in 3 cases and by observing a VA increase with LBBB in 2 cases. The NF and 3 of the NV AP were successfully ablated from within the proximal coronary sinus (CS) guided by recorded potentials at the roof of the CS, and 1 NV AP was ablated via a transseptal approach near the CS os. Conclusions - Left-sided NF and NV AP appear to connect the ventricles with the CS musculature in the region of the CS os. Mapping and successful ablation sites can be guided by recording potentials within or near the CS os.

    View details for DOI 10.1161/CIRCEP.119.007853

    View details for PubMedID 32286853

  • An Irregular Rhythm: What Is the Mechanism? JACC. Clinical electrophysiology Higuchi, S. n., Kumar, U. N., Badhwar, N. n., Tchou, P. n., Scheinman, M. M. 2020; 6 (9): 1205–11

    View details for DOI 10.1016/j.jacep.2020.08.006

    View details for PubMedID 32972562

  • Complex Re-Entrant Arrhythmias Involving the His-Purkinje System: A Structured Approach to Diagnosis and Management. JACC. Clinical electrophysiology Voskoboinik, A. n., Gerstenfeld, E. P., Moss, J. D., Hsia, H. n., Goldberger, J. n., Nazer, B. n., Dewland, T. n., Singh, D. n., Badhwar, N. n., Tchou, P. J., Meriwether, J. N., Sauer, W. n., Danon, A. n., Belhassen, B. n., Scheinman, M. M. 2020; 6 (12): 1488–98


    This study sought to characterize the presentations, electrophysiological features and diagnostic maneuvers for a series of unique arrhythmias involving the HPS.By virtue of its unique anatomy and ion channel composition, the His-Purkinje system (HPS) is prone to a variety of arrhythmic perturbations.The authors present a collaborative multicenter case series of 6 patients with HPS-related arrhythmias. All patients underwent electrophysiological studies using standard multipolar catheters.In 3 patients, both typical and reverse bundle branch re-entry were seen, with 1 patient demonstrating "figure of 8" re-entry likely involving the septal fascicle. One patient presented with systolic dysfunction associated with a high premature ventricular complex burden, with the mechanism being bundle-to-bundle re-entrant beats masquerading as dual response to a single sinus impulse. Two patients were diagnosed with interfascicular re-entry. Diagnosis was aided by careful assessment of HV interval in sinus rhythm and ventricular tachycardia, multipolar catheters to assess the activation sequence of the His-right bundle branch, and fascicles and entrainment of different components of the HPS. Cure of the arrhythmia was achieved by ablation of the right bundle branch block in 3 patients, the left septal fascicle in 2 patients, and the left posterior fascicle in 1 patient.Proper diagnosis of re-entrant arrhythmias involving the HPS may prove challenging. We emphasize a structured approach for diagnosis and effective therapy.

    View details for DOI 10.1016/j.jacep.2020.06.009

    View details for PubMedID 33213808

  • 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


    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

  • Intentional pneumothorax avoids collateral damage: Dynamic phrenic nerve mobilization through intrathoracic insufflation of carbon dioxide. HeartRhythm case reports Shah, R. L., Perino, A. n., Obafemi, O. n., Lee, A. n., Badhwar, N. n. 2019; 5 (9): 480–84

    View details for DOI 10.1016/j.hrcr.2019.07.007

    View details for PubMedID 31934546

    View details for PubMedCentralID PMC6951311

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


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

    View details for DOI 10.1111/jce.13699

    View details for PubMedID 30016007

  • Subxiphoid Hybrid Approach for Epicardial/Endocardial Ablation and LAA Exclusion in Patients with Persistent and Longstanding Atrial Fibrillation. Journal of atrial fibrillation Badhwar, N., Al-Dosari, G., Dukes, J., Lee, R. J. 2018; 11 (1): 2014


    Two patients with long-standing atrial fibrillation (AF) refractory to medical management and with prior pulmonary vein isolation underwent a new hybrid epicardial/endocardial subxyphoid approach for AF ablation and left atrial appendage (LAA) ligation. Pulmonary vein and LA posterior wall isolation, as well as LAA exclusion were achieved in both patients. There were no procedural complications. Both patients remain in sinus rhythm. Both patients are off antiarrhythmic medications.

    View details for DOI 10.4022/jafib.2014

    View details for PubMedID 30455837

    View details for PubMedCentralID PMC6207232

  • Clinical Features and Sites of Ablation for Patients With Incessant Supraventricular Tachycardia From Concealed Nodofascicular and Nodoventricular Tachycardias. JACC. Clinical electrophysiology Han, F. T., Riles, E. M., Badhwar, N., Scheinman, M. M. 2017; 3 (13): 1547-1556


    This study sought to describe the clinical features and sites of successful ablation for incessant nodofascicular (NF) and nodoventricular (NV) tachycardias.Incessant supraventricular tachycardias have been associated with tachycardia-induced cardiomyopathies and have been previously attributed to permanent junctional reciprocating tachycardias, atrial tachycardias, and atrioventricular nodal re-entrant tachycardias. Incessant concealed NF and NV tachycardias have not been described previously.Three cases of incessant concealed NF and NV re-entrant tachycardias were identified from 2 centers.The authors describe 3 cases with incessant supraventricular tachycardia resulting from NV (2 cases) and NF (1 case) pathways. Atrioventricular nodal re-entrant tachycardia was excluded by His synchronous premature ventricular complexes that either delayed or terminated the tachycardia. Ventricular pacing showed constant and progressive fusion in cases 1 and 3. In 2 cases, there was spontaneous initiation with a 1:2 response (cases 1 and 3); the presence of retrograde longitudinal dissociation or marked decremental pathway conduction in cases 1 and 3 sustains these tachycardias. The NV pathway was successfully ablated in the slow pathway region in case 3 and at the right bundle branch in case 1. The NF pathway was successfully ablated within the proximal coronary sinus in case 2.This is the first report of incessant supraventricular tachycardia using concealed NF or NV pathways. These tachycardias demonstrated spontaneous initiation from sinus rhythm with a 1:2 response and retrograde longitudinal dissociation or marked decremental pathway conduction. Successful ablation was achieved at either right-sided sites or within the coronary sinus.

    View details for DOI 10.1016/j.jacep.2017.07.015

    View details for PubMedID 29759837

  • Post-cardioversion ST-segment elevation: a case-based review of the pathophysiology. Journal of thoracic disease Divanji, P., Badhwar, N., Goldschlager, N. 2017; 9 (12): 5503-5506

    View details for DOI 10.21037/jtd.2017.11.82

    View details for PubMedID 29312760

    View details for PubMedCentralID PMC5757058

  • Anatomical and electrical remodeling with incomplete left atrial appendage ligation: Results from the LAALA-AF registry. Journal of cardiovascular electrophysiology Turagam, M., Atkins, D., Earnest, M., Lee, R., Nath, J., Ferrell, R., Bartus, K., Badhwar, N., Rasekh, A., Cheng, J., Di Biase, L., Natale, A., Wilber, D., Lakkireddy, D. 2017; 28 (12): 1433-1442


    The anatomical, electrical, and clinical impact of incomplete Lariat left atrial appendage ligation remains unclear.We studied LAA anatomy pre- and postligation using contrast enhanced-computed tomography (CT) scans in 91 patients with atrial fibrillation (AF) who subsequently underwent catheter ablation (CA).Eleven patients had an incomplete exclusion (12%) with a central leak ranging from 1 to 5 mm. Despite incomplete ligation; the LAA volume were reduced by 67% postprocedurally when compared to preprocedure. In 7 patients with a leak between 1 and 3 mm, there was a 77% reduction in LAA volume beyond the ligation site suggestive of remodeling of the LAA. In 4 patients with larger (4-5 mm) leak the LAA remnants (LAARs) were slightly larger than those with smaller leaks on follow-up CT scan. Three out of the 4 demonstrated LAA electrical activity during CA and underwent isolation of the LAA ostium. Follow-up imaging showed two of these LAARs completely sealed with no communication with the left atrium. There was no significant difference in the AF recurrence rates between the patients who had a leak versus those with complete ligation (4 of 11 [36%] vs. 22 of 80 [27%]; P  =  0.6). Oral anticoagulation was discontinued in all patients with small leaks and 2 patients with large leaks that sealed completely upon follow-up imaging. There were no strokes or TIAs at 12 months.Despite incomplete LAA ligation by Lariat device there is significant anatomical and electrical remodeling that resulted in reduction in LAA size, volume, and electrical activity.

    View details for DOI 10.1111/jce.13343

    View details for PubMedID 28940485

  • Safety and outcomes of cryoablation for ventricular tachyarrhythmias: Results from a multicenter experience HEART RHYTHM Di Biase, L., Al-Ahamad, A., Santangeli, P., Hsia, H. H., Sanchez, J., Bai, R., Bailey, S., Horton, R., Gallinghouse, G. J., Burkhardt, D. J., Lakkireddy, D., Yang, Y., Badhwar, N., Scheinman, M., Tung, R., Dello Russo, A., Pelargonio, G., Casella, M., Tomassoni, G., Shivkumar, K., Natale, A. 2011; 8 (7): 968-974


    Catheter ablation of ventricular arrhythmias (VAs) with cryoenergy has not been widely reported.The purpose of this study was to assess the feasibility and safety of cryoablation for VA.Cases where cryoablation of VA was attempted as the initial strategy or was considered to prevent potential damage to other structures such as the coronary arteries, phrenic nerve, and His bundle were collected. Thirty-three patients with either normal heart or structural heart disease undergoing VA ablation using cryoenergy at six different institutions were enrolled in the study. Epicardial access was obtained when appropriate.Fifteen patients (7 men) underwent endocardial ablation, 13 (9 men) epicardial ablation (from the coronary sinus in 7), and 5 (2 men) aortic cusp ablation. Mean age was 54 ± 8 years, and ejection fraction was 45% ± 5%. In 15 (45%) patients, VAs were successfully ablated, whereas cryoablation was unsuccessful in the remaining 18 (55%) patients. Cryoablation was successful in all parahisian cases (100%). In three patients, epicardial cryoablation was successful after several failed attempts with open irrigated catheter. An aortic dissection occurred during catheter placement in the aortic cusp. At follow-up of 24 ± 5 months, all patients with acute success were free from clinical VA.Use of cryoenergy for ablation of VA has excellent success for arrhythmias near the His bundle; however, success rates at other sites appear less favorable. Cryoablation may be considered as an alternative approach for reducing complications during ablation of VAs originating from sites close to other relevant cardiac structures (conduction system, coronary arteries, phrenic nerve) and, in rare cases, could be used epicardially when radiofrequency energy applications have failed.

    View details for DOI 10.1016/j.hrthm.2011.02.038

    View details for Web of Science ID 000292243400007

    View details for PubMedID 21376835

  • Wolff-Parkinson-White syndrome: where is the pathway? Indian pacing and electrophysiology journal Turakhia, M. P., Scheinman, M., Badhwar, N. 2009; 9 (2): 130-133


    A 31-year old male presented with atrial fibrillation and ventricular preexcitation that was positive in leads V1-V4, negative in lead II, and positive in lead AVR. The patient was cardioverted and invasive electrophysiologic study was performed. Based on the ECG findings, the coronary sinus and its branches were interrogated during orthodromic atrioventricular reentrant tachycardia. The earliest local activation was seen in the true coronary sinus lumen at the bifurcation of the posterolateral branch. Radiofrequency energy application at this area led to loss of preexcitation. When localizing left septal and posterior accessory pathways, ventricular preexcitation that is both negative in II and positive in AVR has been shown in previous studies to be highly sensitive and specific for a subepicardial location. Therefore, investigation of the coronary sinus and its branches may allow for effective ablation without the need for left ventricular access.

    View details for PubMedID 19308285

  • 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


    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