Amplitude of QRS complex within initial 40 ms in V2 (V2QRSi40): Novel electrocardiographic criterion for predicting accurate localization of outflow tract ventricular arrhythmia origin
The initial depolarization vector of outflow tract (OT) ventricular arrhythmia (VA) varies in different origins, which may help to predict OT-VA origin more accurately. (Source: Heart Rhythm)
Source: Heart Rhythm - July 9, 2020 Category: Cardiology Authors: Yu Xia, Zheng Liu, Jun Liu, Xiaofeng Li, Hao Zhang, Lijuan Fu, Miao Yu, Pihua Fang Source Type: research

Towards Detection of Conduction Tissue During Cardiac Surgery: Light at the End of the Tunnel?
Postoperative conduction block requiring lifetime pacemaker placement continues to be a considerable source of morbidity for patients undergoing repair of congenital heart defects. Damage to the cardiac conduction system (CCS) during surgical procedures is thought to be a major cause of the conduction block. Intraoperative identification and avoidance of the CCS is thus a key strategy to improve surgical outcomes. In order to avoid conduction tissue damage and mitigate morbidity a number of approaches have been developed. (Source: Heart Rhythm)
Source: Heart Rhythm - July 9, 2020 Category: Cardiology Authors: Frank B. Sachse, Jordan Johnson, Brian Cottle, Abhijit Mondal, Robert Hitchcock, Aditya K. Kaza Source Type: research

EP News: Allied Professionals
In this paper, the authors (Poole et al J Am Coll Cardiol. 2020;75:3105-3118. PMID 32586583) provide expanded results of an important secondary endpoint of the CABANA (Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) trial, the recurrence of atrial fibrillation (AF). In the CABANA trial, 2204 patients with symptomatic AF and risk factors for stroke were randomized to catheter ablation or drug therapy with a primary endpoint was a composite of death, stroke, major bleeding or cardiac arrest during 5 years of follow-up. (Source: Heart Rhythm)
Source: Heart Rhythm - July 8, 2020 Category: Cardiology Authors: Erica S. Zado Source Type: research

EP News: Basic and Translational
In the current study, Ouyang et al (Nature 2020;580:252; PMID:32269341) used a video-based deep learning algorithm-EchoNet-Dynamic-to assess left ventricular ejection fraction from echocardiogram. The model leverages information across multiple cardiac cycles and accurately segments the left ventricle with a Dice similarity coefficient of 0.92, predicts ejection fraction with a mean absolute error of 4.1% and reliably classifies heart failure with reduced ejection fraction (area under the curve of 0.97). (Source: Heart Rhythm)
Source: Heart Rhythm - July 8, 2020 Category: Cardiology Authors: Nipavan Chiamvimonvat Source Type: research

A long RP supraventricular tachycardia with the earliest atrial activation at the His-bundle region: What is the ablation target?
A 72-year-old woman with a prior history of catheter ablation for supraventricular tachycardia in another hospital presented with recurrent episodes of palpitations. Twelve-lead ECG recorded during the palpitation showed a long RP narrow QRS tachycardia with a second-degree atrioventricular (AV) block (Figure 1A). At electrophysiologic study, the ventriculoatrial (VA) conduction was concentric and decremental. Programmed atrial stimulation reproducibly induced a long RP narrow QRS tachycardia. The earliest atrial activation (EAS) during the tachycardia was at the His-bundle region. (Source: Heart Rhythm)
Source: Heart Rhythm - July 6, 2020 Category: Cardiology Authors: Akira Mizukami, Mitsunori Maruyama, Akihiko Matsumura, Tetsuo Sasano Source Type: research

Sudden Cardiac Death Risk-Stratification in Ventricular Preexcitation: A Tale of Two Eras
Primary prevention of sudden cardiac death (SCD) is an issue well known to electrophysiologists. In asymptomatic patients with ventricular preexcitation (VPE), where the estimated annual SCD risk may be as low as 1 in a 1000, risk assessment may be particularly difficult (1). However, it is axiomatic that you cannot make an asymptomatic individual feel better, but you cannot develop a therapeutic plan for someone who has died. Such is the conundrum of risk stratification. (Source: Heart Rhythm)
Source: Heart Rhythm - July 4, 2020 Category: Cardiology Authors: Eric N. Prystowsky, Leonard Steinberg Source Type: research

EP News Clinical July 1, 2020
Osmancik and colleagues (J Am Coll Cardiol. 2020; 75:3122-3135. PMID: 32586585) compared left atrial appendage closure (LAAC) with direct oral anticoagulants in a multicenter, randomized, noninferiority trial. A high-risk patient cohort (CHA2DS2-VASc: 4.7 ± 1.5) was randomized to receive LAAC (n = 201) or DOAC (n = 201). At 19.9 months of follow-up, the annual rates of the primary outcome were 10.99% with LAAC and 13.42% with DOAC (HR: 0.84; p = 0.44; p = 0.004 for noninferiority). There were no differences between groups for the components of the c omposite endpoint: all-stroke/TIA (HR: 1.00), clinically significan...
Source: Heart Rhythm - July 4, 2020 Category: Cardiology Authors: N. A. Mark Estes Source Type: research

EP News: Case Reports
As the number of patients inflicted with COVID-19 continue to increase, more is learned about the cardiovascular manifestations of the disease. The disease can result in severe systemic stress resulting in respiratory and hemodynamic failure. Takotsubo cardiomyopathy is reversible left ventricular apical ballooning typically mediated by severe stress in the absence of significant coronary artery stenosis. Khalid et al. (DOI: https://doi.org/10.1016/j.hrcr.2020.05.020) share a case of a 76-year-old female who was admitted to the intensive care unit (ICU) due to acute respiratory failure secondary to COVID-19 infection. (Source: Heart Rhythm)
Source: Heart Rhythm - July 4, 2020 Category: Cardiology Authors: T. Jared Bunch Source Type: research

Prophylactic (hydroxy)chloroquine in COVID-19: potential relevance for cardiac arrhythmia risk
(Hydroxy)chloroquine ((H)CQ) is being investigated as treatment for COVID-19, but studies have so far demonstrated either no or a small benefit. However, these studies have been mostly performed in patients admitted to hospital and hence likely already (severely) affected. Another suggested approach employs prophylactic (H)CQ treatment aimed at preventing either SARS-CoV-2 infection or development of disease. A substantial number of clinical trials are planned or underway aimed at assessing the prophylactic benefit of (H)CQ. (Source: Heart Rhythm)
Source: Heart Rhythm - July 2, 2020 Category: Cardiology Authors: Joost A. Offerhaus, Arthur A.M. Wilde, Carol Ann Remme Source Type: research

Simultaneous epicardial-endocardial mapping of the sinus node in humans with structural heart disease: Impact of overdrive suppression on sino-atrial exits
The 3-dimensional nature of sino-atrial node (SAN) function has not previously been characterised in the intact human heart. (Source: Heart Rhythm)
Source: Heart Rhythm - July 2, 2020 Category: Cardiology Authors: Ramanathan Parameswaran, Geoffrey Lee, Gwilym M. Morris, Alistair Royse, John Goldblatt, Marco Larobina, Troy Watts, Chrishan J. Nalliah, Geoffrey Wong, Ahmed M. Al-Kaisey, Robert D. Anderson, Aleksandr Voskoboinik, Hariharan Sugumar, David Chieng, Prasha Source Type: research

INCIDENCE OF ARRHYTHMIAS AND ELECTROCARDIOGRAPHIC ABNORMALITIES IN SYMPTOMATIC PEDIATRIC PATIENTS WITH PCR POSITIVE SARS-CoV-2 INFECTION INCLUDING DRUG INDUCED CHANGES IN THE CORRECTED QT INTERVAL (QTc).
There is limited data regarding the electrophysiological abnormalities and arrhythmias in children with COVID-19, including those associated with treatment using potentially pro-arrhythmic Hydroxychloroquine (HCQ) and Azithromycin (AZN). (Source: Heart Rhythm)
Source: Heart Rhythm - July 1, 2020 Category: Cardiology Authors: Sharmeen Samuel, Richard A. Friedman, Chetan Sharma, Madhusudan Ganigara, Elizabeth Mitchell, Charles Schleien, Andrew D. Blaufox Source Type: research

Transvenous Phrenic Nerve Stimulation for Central Sleep Apnea is Safe and Effective in Patients with Concomitant Cardiac Devices
Central sleep apnea is common in heart failure patients. Transvenous phrenic nerve stimulation (TPNS) requires placing a lead to stimulate the phrenic nerve and activate the diaphragm. Data are lacking concerning the safety and efficacy of TPNS in patients with concomitant cardiovascular implantable electronic devices (CIEDs). (Source: Heart Rhythm)
Source: Heart Rhythm - June 30, 2020 Category: Cardiology Authors: Hemal M. Nayak, Raj Patel, Scott McKane, Kristofer J. James, Timothy E. Meyer, Robin E. Germany, Christoph Stellbrink, Maria Rosa Costanzo, Ralph Augostini Source Type: research

Common and rare susceptibility genetic variants predisposing to Brugada Syndrome in Thailand
Mutations in SCN5A are rarely found in Thai patients with Brugada syndrome (BrS). Recent evidence suggested that common genetic variation may underlie BrS in a complex inheritance model. (Source: Heart Rhythm)
Source: Heart Rhythm - June 30, 2020 Category: Cardiology Authors: Pattarapong Makarawate, Charlotte Glinge, Apichai Khongphatthanayothin, Roddy Walsh, John Mauleekoonphairoj, Montawatt Amnueypol, Somchai Prechawat, Wanwarang Wongcharoen, Rungroj Krittayaphong, Alisara Anannab, Peter Lichtner, Thomas Meitinger, Fleur V.Y Source Type: research

A fast irregular tachycardia with changing QRS configuration in a 29-year-old man
A 29-year-old man came to the emergency department after a collapse during a bicycle race. He was conscious, complaining about dizziness and palpitations. He never had these complaints before. The 12-lead electrocardiogram (ECG) recorded on arrival is shown in Figure  1A. The arrhythmia was terminated by electrical cardioversion. The ECG in Figure 1B was recorded shortly thereafter. (Source: Heart Rhythm)
Source: Heart Rhythm - June 29, 2020 Category: Cardiology Authors: Hein J. Wellens Tags: Josephson and Wellens ECG Lessons: A Monthly Visit to the 12 Lead ECG Source Type: research

Macro-reentrant Biatrial Tachycardia Relevant to Interatrial Septal Incisions after Mitral Valve Surgery: Electrophysiological Characteristics and Ablation Strategy
Macroreentrant biatrial tachycardia (BiAT) relevant to interatrial septal incisions following MV surgery has been rarely reported. (Source: Heart Rhythm)
Source: Heart Rhythm - June 29, 2020 Category: Cardiology Authors: Jinlin Zhang, Wei Hu, Anquan Zhao, Gang Yang, Qingyong Zhang, Xi Su, Minglong Chen Source Type: research

Diagnostic yield and long-term outcome of non-ischemic sudden cardiac arrest survivors and their relatives - results from a tertiary referral center
Cardiac arrest may be the first manifestation in the majority of inherited cardiac diseases. International guidelines recommend screening of relatives of Sudden Cardiac Arrest (SCA) survivors if an inherited cardiac disorder is suspected. (Source: Heart Rhythm)
Source: Heart Rhythm - June 28, 2020 Category: Cardiology Authors: Elisabeth M ütze Jacobsen, Benjamin Lautrup Hansen, Amalie Kjerrumgaard, Jacob Tfelt-Hansen, Christian Hassager, Jesper Kjaergaard, Alex Hørby Christensen, Henning Bundgaard, Bo Gregers Winkel Source Type: research

Effects of Hydroxychloroquine Treatment on QT Interval
Hydroxychloroquine (HCQ) has been promoted as a potential treatment for COVID-19 but there are safety concerns. (Source: Heart Rhythm)
Source: Heart Rhythm - June 28, 2020 Category: Cardiology Authors: Matthew Hooks, Bradley Bart, Orly Vardeny, Anders Westanmo, Sel çuk Adabag Source Type: research

His Bundle and Left Bundle Pacing with Optimised Atrio-ventricular Delay Achieve Superior Electrical Synchrony over Endocardial and Epicardial Pacing in Left Bundle Branch Block Patients
His bundle pacing (HBP) and left bundle pacing (LBP) are emerging as novel delivery methods for cardiac resynchronisation therapy (CRT) in heart failure patients with left bundle branch block (LBBB). HBP and LBP have never been compared to biventricular endocardial (BiV-endo) pacing. Furthermore, there are indications of negative effects of LBP on right ventricular (RV) activation times (ATs), but these effects have not been quantified. (Source: Heart Rhythm)
Source: Heart Rhythm - June 27, 2020 Category: Cardiology Authors: Marina Strocchi, Angela W.C. Lee, Aurel Neic, Julien Bouyssier, Karli Gillette, Gernot Plank, Mark K. Elliott, Justin Gould, Jonathan M. Behar, Baldeep Sidhu, Vishal Mehta, Martin J. Bishop, Edward J. Vigmond, Christopher A. Rinaldi, Steven A. Niederer Source Type: research

Follow-Up Imaging after Left Atrial Appendage Closure
Because device-related thrombus (DRT) portends a poor prognosis after left atrial appendage closure with the Watchman device, surveillance transesophageal echocardiograms (TEEs) are recommended at 45 days and 1 year. However, oral anticoagulants are just stopped at 45 days, rendering this early TEE unlikely to detect DRT. Indeed, DRT is most likely to occur after instituting aspirin monotherapy. (Source: Heart Rhythm)
Source: Heart Rhythm - June 26, 2020 Category: Cardiology Authors: Kenji Kuroki, Shephal K. Doshi, William Whang, Sarina Vanderzee, Crystal B. Ducharme, Yoshinari Enomoto, Sam Hanon, Jacob S. Koruth, Marc A. Miller, Subbarao Choudry, Aamir Sofi, Noelle Langan, Betsy Ellsworth, Srinivas R. Dukkipati, Vivek Y. Reddy Source Type: research

Percutaneous Recanalization of Superior Vena Cava Occlusions for Cardiac Implantable Electronic Device Implantation – Tools and Techniques
Widespread use of indwelling intravascular catheters and cardiac implantable electronic devices (CIEDs) has led to an increase in venous occlusions involving the subclavian system,1 and rarely, the superior vena cava (SVC).2 Although some patients with SVC occlusion present with debilitating symptoms consistent with SVC syndrome, others have minimal symptoms or are entirely asymptomatic. When CIED leads are present within an SVC occlusion, contemporary transvenous lead extraction (TLE) tools can be used as a conduit to maintain vascular access after lead removal. (Source: Heart Rhythm)
Source: Heart Rhythm - June 26, 2020 Category: Cardiology Authors: Naga Venkata K. Pothineni, C.Anwar A. Chahal, David S. Frankel, Fermin C. Garcia, Jay Giri, Joshua M. Cooper, Robert D. Schaller Source Type: research

Bipolar radiofrequency ablation for ventricular tachycardias originating from the interventricular septum: safety and efficacy in a pilot cohort study
Interest has grown in recent years for bipolar radiofrequency ablation (B-RFA). However, indications and outcome in patients with ventricular tachycardia (VT) are still to be defined. (Source: Heart Rhythm)
Source: Heart Rhythm - June 26, 2020 Category: Cardiology Authors: Paolo Della Bella, Giovanni Peretto, Gabriele Paglino, Caterina Bisceglia, Andrea Radinovic, Simone Sala, Francesca Baratto, Luca Limite, Manuela Cireddu, Alessandra Marzi, Giuseppe D ’Angelo, Pasquale Vergara, Simone Gulletta, Patrizio Mazzone, Antonio Source Type: research

COVID-19 Cardiac Injury: Implications for Long-Term Surveillance and Outcomes in Survivors
Up to 20-30% of patients hospitalized with coronavirus disease (COVID-19) have evidence of myocardial involvement. Acute cardiac injury in patients hospitalized with COVID-19 is associated with higher morbidity and mortality. There are no data on how acute treatment for COVID-19 may affect convalescent phase or long-term cardiac recovery and function. Myocarditis from other viral pathogens can evolve into overt or subclinical myocardial dysfunction, and sudden death has been described in the convalescent phase of viral myocarditis. (Source: Heart Rhythm)
Source: Heart Rhythm - June 26, 2020 Category: Cardiology Authors: Raul D. Mitrani, Nitika Dabas, Jeffrey J. Goldberger Source Type: research

In-Hospital and Long-term Outcomes among Patients with Spontaneous Coronary Artery Dissection presenting with Ventricular Tachycardia/Fibrillation
Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction (MI) in young to middle-aged women. Ventricular tachycardia/ventricular fibrillation (VT/VF) may complicate acute SCAD presentations and the long-term outcomes are unknown. (Source: Heart Rhythm)
Source: Heart Rhythm - June 23, 2020 Category: Cardiology Authors: Christopher C. Cheung, Andrew Starovoytov, Ashkan Parsa, Jason G. Andrade, Andrew D. Krahn, Matthew Bennett, Jacqueline Saw Source Type: research

Cryoballoon Ablation of Pulmonary Veins for Persistent Atrial Fibrillation: Results From the Multicenter STOP Persistent AF Trial
Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation to treat patients with symptomatic drug-refractory atrial fibrillation (AF). (Source: Heart Rhythm)
Source: Heart Rhythm - June 23, 2020 Category: Cardiology Authors: Wilber W. Su, Vivek Y. Reddy, Kabir Bhasin, Jean Champagne, Robert M. Sangrigoli, Kendra M. Braegelmann, Fred J. Kueffer, Paul Novak, Sanjaya K. Gupta, Teiichi Yamane, Hugh Calkins, STOP Persistent AF Investigators Source Type: research

Signature Signal Strategy: Electrogram Based Ventricular Tachycardia Mapping Nayyar et al. Signature electrogram based VT ablation
Multiple decades of work have recognized complexities of substrate responsible for ventricular tachycardia (VT). There is enough evidence that three critical components of a re-entrant VT circuit, namely region of slow conduction, zone of unidirectional block and exit site, are located in spatial vicinity to each other in the ventricular scar. Each of these express characteristic electrograms in sinus rhythm, at initiation of VT and during VT, respectively. Despite this, abnormal electrograms are widely targeted without appreciation of these signature electrograms during contemporary VT ablation. (Source: Heart Rhythm)
Source: Heart Rhythm - June 23, 2020 Category: Cardiology Authors: Sachin Nayyar, Eugene Downar, Abhishek P. Bhaskaran, St éphane Massé, Kumaraswamy Nanthakumar Source Type: research

COVID-19 and Cardiac Arrhythmias
Early studies suggest that coronavirus disease 2019 (COVID-19) is associated with a high incidence of cardiac arrhythmias. SARS-CoV-2 infection may cause injury to cardiac myocytes and increase arrhythmia risk. (Source: Heart Rhythm)
Source: Heart Rhythm - June 22, 2020 Category: Cardiology Authors: Anjali Bhatla, Michael M. Mayer, Srinath Adusumalli, Matthew C. Hyman, Eric Oh, Ann Tierney, Juwann Moss, Anwar A. Chahal, George Anesi, Srinivas Denduluri, Christopher M. Domenico, Jeffrey Arkles, Benjamin S. Abella, John R. Bullinga, David J. Callans, S Source Type: research

Reconsidering the Multiple Wavelet Hypothesis of Atrial Fibrillation
Moe/Abildskov proposed the multiple wavelet hypothesis of atrial fibrillation (AF) based on observations in the canine vagal nerve stimulation (VNS) AF model. Data from mapping studies in in vitro canine AF model by Allessie et al. evaluated the Moe/Abildskov hypothesis, concluding that a critical number of wavelets sustained AF. (Source: Heart Rhythm)
Source: Heart Rhythm - June 21, 2020 Category: Cardiology Authors: Seungyup Lee, Celeen M. Khrestian, Jayakumar Sahadevan, Albert L. Waldo Source Type: research

Skin sympathetic nerve activity in patients with obstructive sleep apnea
Obstructive sleep apnea (OSA) is associated with increased cardiac arrhythmia and sudden cardiac death. We recently developed a new method (neuECG) to non-invasively measure electrocardiogram and skin sympathetic nerve activity (SKNA). (Source: Heart Rhythm)
Source: Heart Rhythm - June 19, 2020 Category: Cardiology Authors: Wenbo He, Yuzhu Tang, Guannan Meng, Danning Wang, Johnson Wong, Gloria A. Mitscher, David Adams, Thomas H. Everett, Peng-Sheng Chen, Shalini Manchanda Source Type: research

Drivers of Hospitalization in Atrial Fibrillation: A Contemporary Review
Atrial fibrillation (AF) related hospitalization has risen over the last two decades and is the most influential determinant of total disease-related expenditure. In this review article, we describe several identified drivers for hospitalization from several registries and large-scale clinical trials, including key cardiovascular and non-traditional risk factors. We also discuss available assessment tools for discerning overall risk of hospitalization, including AF symptom scores, thrombosis and bleeding disposition, and non-invasive cardiac structural assessment. (Source: Heart Rhythm)
Source: Heart Rhythm - June 18, 2020 Category: Cardiology Authors: Aditya Bhat, Shaun Khanna, Henry H.L. Chen, Gary C.H. Gan, C. Raina MacIntyre, Timothy C. Tan Source Type: research

Evidence of two conduction exits of moderator band: Findings from activation and pace mapping study
The moderator band (MB) is an endocavitary structure with only 2 exits to the bulk of ventricular myocardium. Whether this may lead to specific electrophysiological characteristics remains unknown. (Source: Heart Rhythm)
Source: Heart Rhythm - June 17, 2020 Category: Cardiology Authors: Chen-Xi Jiang, De-Yong Long, Meng-Meng Li, Cai-Hua Sang, Ri-Bo Tang, Wei Wang, Song-Nan Li, Xue-Yuan Guo, Rong Bai, Xin Du, Jian-Zeng Dong, Chang-Sheng Ma Source Type: research

European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) expert consensus on risk assessment in cardiac arrhythmias: use the right tool for the right outcome, in the right population
Patients with cardiac diseases or conditions with high risk of developing cardiac diseases undergo risk assessment by cardiologists, primary care physicians, and scientists based on referral for more advanced risk assessment strategies, institution of preventive treatments, counselling of patients and their relatives, and selection of patients for scientific trials. The various methods used for risk assessment differ with respect to availability, complexity, and usefulness in different patient populations. (Source: Heart Rhythm)
Source: Heart Rhythm - June 15, 2020 Category: Cardiology Authors: Jens Cosedis Nielsen, Yenn-Jiang Lin, Marcio Jansen de Oliveira Figueiredo, Alireza Sepehri Shamloo, Alberto Alfie, Serge Boveda, Nikolaos Dagres, Dario Di Toro, Lee L. Eckhardt, Kenneth Ellenbogen, Carina Hardy, Takanori Ikeda, Aparna Jaswal, Elizabeth K Source Type: research

EP News: Allied Professionals
Using a national registry of patients with cardiac inherited disease (CID), the authors (Rucinski et al. J Am Coll Cardiol. 2020;75:2698-2707. PMID:32466885) sought to describe the profile of patients presenting with resuscitated sudden cardiac death (RSCD). People in New Zealand presenting with RSCD are evaluated using a standardized approach and those determined to have CID are included in the registry. Patients were classified based on standard diagnostic criteria for each diagnostic category including long QT syndrome (LQTS), Brugada syndrome (BrS), hypertrophic cardiomyopathy (HCM), catecholaminergic polymorphic ventr...
Source: Heart Rhythm - June 14, 2020 Category: Cardiology Authors: Erica S. Zado Source Type: research

About the different faces of mexiletine
The electrophysiological working mechanisms underlying muscle contraction and relaxation have been subject of investigations for over 140 years, and already in those early years the considerable overlap between the electrophysiology of cardiac and skeletal muscle was appreciated.(1) This has brought insights in electrophysiology and pathophysiology and has brought progress in the recognition and treatment of disorders in both cardiology and neurology in the decades thereafter. In part due to this progress, in the late 1960 ’s, 1970’s and 1980’s nearly all of our currently available anti-arrhythmic drugs w...
Source: Heart Rhythm - June 13, 2020 Category: Cardiology Authors: Pieter G. Postema Source Type: research

Guidance for rebooting electrophysiology through the COVID-19 pandemic from the Heart Rhythm Society and the American Heart Association Electrocardiography and Arrhythmias Committee of the Council on Clinical Cardiology
Coronavirus disease 2019 (COVID-19) has presented substantial challenges to patient care and impacted health care delivery, including cardiac electrophysiology practice throughout the globe. Based upon the undetermined course and regional variability of the pandemic, there is uncertainty as to how and when to resume and deliver electrophysiology services for arrhythmia patients. This joint document from representatives of the Heart Rhythm Society, American Heart Association, and American College of Cardiology seeks to provide guidance for clinicians and institutions reestablishing safe electrophysiological care. (Source: Heart Rhythm)
Source: Heart Rhythm - June 12, 2020 Category: Cardiology Authors: Dhanunjaya R. Lakkireddy, Mina K. Chung, Thomas F. Deering, Rakesh Gopinathannair, Christine M. Albert, Laurence M. Epstein, Clifford V. Harding, Jodie L. Hurwitz, Courtney C. Jeffery, Andrew D. Krahn, Fred M. Kusumoto, Rachel Lampert, Moussa Mansour, And Source Type: research

Entrainment of a wide QRS complex tachycardia with progressive atrial delay: What is the mechanism?
A 47-year-old woman underwent electrophysiological testing of a wide QRS complex tachycardia (WCT). At baseline, atrio-Hisian and His-ventricular intervals were normal. Neither atrial extrastimulation nor atrial burst pacing revealed any evidence of dual atrioventricular (AV) nodal physiology and apparent ventricular pre-excitation, and ventriculoatrial (VA) conduction appeared to be absent. Atrial extrastimulation induced a WCT exhibiting an eccentric atrial activation sequence (Figure-1A). During the WCT, ventricular overdrive pacing (VOP) from the right ventricular apex (RVA) resulted in the progressive prolongation of ...
Source: Heart Rhythm - June 11, 2020 Category: Cardiology Authors: Taihei Itoh, Masaomi Kimura, Kimitaka Nishizaki, Hirofumi Tomita Source Type: research

Behavior of the PR Interval with Increasing Heart Rate in Patients with COVID-19
Myriad manifestations of cardiovascular involvement are described in Coronavirus disease 2019 (COVID-19) but there have been no reports of COVID-19 affecting the cardiac conduction system. The PR interval on the electrocardiogram (ECG) normally shortens with increasing heart rate (HR). We encountered a COVID-19 patient manifesting Mobitz 1 atrioventricular (AV) block which normalized as he improved, prompting us to investigate PR interval behavior in COVID-19. (Source: Heart Rhythm)
Source: Heart Rhythm - June 11, 2020 Category: Cardiology Authors: Behzad B. Pavri, Juergen Kloo, Darius Farzad, Joshua M. Riley Source Type: research

HRS/EHRA/APHRS/LAHRS/ACC/AHA worldwide practice update for telehealth and arrhythmia monitoring during and after a pandemic
Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), started in the city of Wuhan late in 2019. Within a few months, the disease spread toward all parts of the world and was declared a pandemic on March 11, 2020. The current health care dilemma worldwide is how to sustain the capacity for quality services not only for those suffering from COVID-19 but also for non-COVID-19 patients, all while protecting physicians, nurses, and other allied health care workers. (Source: Heart Rhythm)
Source: Heart Rhythm - June 11, 2020 Category: Cardiology Authors: Niraj Varma, Nassir F. Marrouche, Luis Aguinaga, Christine M. Albert, Elena Arbelo, Jong-Il Choi, Mina K. Chung, Giulio Conte, Lilas Dagher, Laurence M. Epstein, Hamid Ghanbari, Janet K. Han, Hein Heidbuchel, He Huang, Dhanunjaya R. Lakkireddy, Tachapong Source Type: research

Reply to the Editor —Differentiation of atrioventricular nodal reentrant tachycardia and nodofascicular reentrant tachycardia
We appreciate the comments by Drs Chin and Chen on our case of nodofascicular reentry. The authors contend that our patient ’s postpacing interval–tachycardia cycle length (PPI–TCL) falls in a gray zone where atrioventricular nodal reentrant tachycardia (AVNRT) cannot be excluded. We respectfully disagree. (Source: Heart Rhythm)
Source: Heart Rhythm - June 8, 2020 Category: Cardiology Authors: Mathew Ortman, Reginald T. Ho Tags: Letter to the Editor Source Type: research

Author ’s Reply to Differentiation of atrioventricular nodal reentry tachycardia and nodofascicular reentry tachycardia
We appreciate the comments by Drs. Chin and Chen on our case of nodofascicular reentry. The authors contend that our patient ’s post pacing interval – tachycardia cycle length (PPI-TCL) falls in a gray zone where atrioventricular nodal reentry tachycardia (AVNRT) cannot be excluded. We respectfully disagree. (Source: Heart Rhythm)
Source: Heart Rhythm - June 8, 2020 Category: Cardiology Authors: Mathew Ortman, Reginald T. Ho Source Type: research

Letter to the Editor —Differentiation of atrioventricular nodal reentrant tachycardia and nodofascicular reentrant tachycardia
We read the interesting case of supraventricular tachycardia with ventriculoatrial dissociation reported by Ortman et  al.1 In that case, atrioventricular nodal reentrant tachycardia (AVNRT) with upper common pathway block and nodofascicular reentrant tachycardia (NFRT) were listed in the differential diagnosis. The His-refractory premature ventricular complex reset the timing of the His potential. NFRT and atypic al AVNRT with bystander nodofascicular pathway both are possible diagnoses. After ventricular entrainment pacing, the postpacing interval–tachycardia cycle length (PPP–TCL) was (Source: Heart Rhythm)
Source: Heart Rhythm - June 7, 2020 Category: Cardiology Authors: Chye-Gen Chin, Wei-Ta Chen Tags: Letter to the Editor Source Type: research

Trends in Utilization and Spending on Remote Monitoring of Pacemakers and Implantable Cardioverter-Defibrillators among Medicare Beneficiaries
National trends and costs associated with remote and in-office interrogations of pacemakers and implantable cardioverter-defibrillators (ICDs) have not been previously described. (Source: Heart Rhythm)
Source: Heart Rhythm - June 7, 2020 Category: Cardiology Authors: Jessica N. Holtzman, Rishi K. Wadhera, Eunhee Choi, Tianyi Zhao, Eric A. Secemsky, Ariane M. Fraiche, Changyu Shen, Daniel B. Kramer Source Type: research

Letter to the Editor - Differentiation of atrioventricular nodal reentry tachycardia and nodofascicular reentry tachycardia
We read the interesting case of supraventricular tachycardia with ventriculo-atrial dissociation.1 by Ortman M, et al. In this case, atrioventricular nodal reentry tachycardia (AVNRT) with upper common pathway block and nodofascicular reentry tachycardia (NFRT) were listed on the differential. The His refractory premature ventricular complex (HRPVC) reset the timing of His potential. NFRT and atypical AVNRT with bystander NF pathway are both possible diagnoses. After ventricular entrainment pacing, the post pacing interval (PPI) – tachycardia cycle length (TCL) was less than 115ms. (Source: Heart Rhythm)
Source: Heart Rhythm - June 7, 2020 Category: Cardiology Authors: Chye-Gen Chin, Wei-Ta Chen Source Type: research

The Answers to Questions Surrounding Left Cardiac Sympathetic Denervation are in the Library, Covered by Dust
More than 100 years have elapsed since in 1916 Thomas Jonnesco performed the first left cardiac sympathetic denervation (LCSD) in a patient with intractable angina and the interest for the procedure waxed and waned over the years1,2. Once it became clear that LCSD had a role in managing the long QT syndrome (LQTS)3, questions about its mechanism(s) of action were addressed in the experimental laboratory4. (Source: Heart Rhythm)
Source: Heart Rhythm - June 7, 2020 Category: Cardiology Authors: Peter J. Schwartz Source Type: research

Evaluation of mexiletine effect on conduction delay and bradyarrhythmic complications in patients with myotonic dystrophy type 1 over long-term follow-up
Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized by progressive cardiac conduction impairment, arrhythmias and sudden death. Mexiletine is a sodium-channel blocker drug used in such patients for the treatment of myotonia, even if definitive proof of its safety over long-term follow-up is lacking (Source: Heart Rhythm)
Source: Heart Rhythm - June 6, 2020 Category: Cardiology Authors: Riccardo Vio, Alessandro Zorzi, Luca Bello, Virginia Bozzoni, Annalisa Botta, Francesco Rivezzi, Loira Leoni, Federico Migliore, Emanuele Bertaglia, Sabino Iliceto, Elena Pegoraro, Domenico Corrado, Chiara Calore Source Type: research

High-throughput discovery of trafficking-deficient variants in the cardiac potassium channel KV11.1
KCHN2 encodes the KV11.1 potassium channel responsible for IKr, a major repolarization current during the cardiomyocyte action potential. Variants in KCNH2 that lead to decreased IKr have been associated with Type 2 Long QT syndrome (LQT2). The mechanism of LQT2 is most often induced loss of KV11.1 trafficking to the cell surface. Accurately discriminating between variants with normal and abnormal trafficking would aid in understanding the deleterious nature of these variants; however, the volume of reported nonsynonymous KCNH2 variants precludes the use of conventional methods for functional study. (Source: Heart Rhythm)
Source: Heart Rhythm - June 5, 2020 Category: Cardiology Authors: Krystian A. Kozek, Andrew M. Glazer, Chai-Ann Ng, Daniel Blackwell, Christian L. Egly, Loren R. Vanags, Marcia Blair, Devyn Mitchell, Kenneth A. Matreyek, Douglas M. Fowler, Bjorn C. Knollmann, Jamie I. Vandenberg, Dan M. Roden, Brett M. Kroncke Source Type: research

EP News: Clinical
Aquaro et  al (J Am Coll Cardiol 2020;75:2753–2765, PMID 32498802) evaluated the prognostic role of cardiac magnetic resonance (CMR) phenotype in patients with definite arrhythmogenic right ventricular cardiomyopathy (ARVC) and the effectiveness of the novel 5-year ARVC risk score in predicting cardiac eve nts based on CMR presentations. The multicenter prospective registry included 140 patients. The combined endpoint was sudden cardiac death, appropriate implantable cardioverter–defibrillator (ICD) intervention, and aborted cardiac arrest. (Source: Heart Rhythm)
Source: Heart Rhythm - June 4, 2020 Category: Cardiology Authors: N.A. Mark Estes Tags: EP NEWS Source Type: research

Catheter Ablation of Intra-Atrial Reentrant/Focal Tachycardia in Adult Congenital Heart Disease: Value of Final Programmed Atrial Stimulation
While outcomes of intra-atrial reentrant/focal atrial tachycardia (IART/FAT) catheter ablation have considerably improved in adult congenital heart disease (ACHD), recurrences remain common with different circuits frequently encountered. (Source: Heart Rhythm)
Source: Heart Rhythm - June 4, 2020 Category: Cardiology Authors: Victor Waldmann, Denis Amet, Alexandre Zhao, Magalie Ladouceur, Akli Otmani, Clement Karsenty, Alice Maltret, Gilles Soulat, Elie Mousseaux, Thomas Lavergne, Xavier Jouven, Laurence Iserin, Eloi Marijon Source Type: research

Congratulations Frank Marcus On His Retirement at the Age of 92
I, Hugh Calkins, received an email last week from Frank Marcus. He informed me that he was going to retire in June 2020 at the age of 92 years. This email motivated me to reflect on my own relationship with Frank and also on his remarkable career and contributions to clinical electrophysiology. Frank ’s connection to Richard Hauer motivated this joint reflection. (Source: Heart Rhythm)
Source: Heart Rhythm - June 4, 2020 Category: Cardiology Authors: Hugh Calkins, Richard Hauer Source Type: research

Long-term percentage of ventricular pacing in patients requiring pacemaker implantation after transcatheter aortic valve replacement. A multicenter 10 years ’ experience.
Recent studies suggest that atrio-ventricular (A-V) conduction may recover after pacemaker (PM) implantation following transcatheter aortic valve replacement (TAVR), but little is known on long-term follow-up of such patients. (Source: Heart Rhythm)
Source: Heart Rhythm - June 4, 2020 Category: Cardiology Authors: Enrico Baldi, Miriam Compagnone, Daniele Errigo, Marco Ferlini, Matteo Ziacchi, Davide Castagno, Alessandro Minguzzi, Andrea Demarchi, Simone Savastano, Francesco Bruno, Pier Giorgio Golzio, Tullio Palmerini, Francesco Saia, Ciro Di Giacomo, Silvia Mauri, Source Type: research

Management and Long-term Outcomes Associated with Recalled Implantable Cardioverter-defibrillator leads: A Multicenter Experience
No comparative study of outcomes in Riata ® and Sprint Fidelis® leads undergoing lead extraction (LE), lead abandonment (LA), and generator change only (GC) has been published. (Source: Heart Rhythm)
Source: Heart Rhythm - June 4, 2020 Category: Cardiology Authors: Philip L. Mar, Anub John, Sundeep Kumar, Neil Barry, Guanhua Chen, Sarah Longserre, Rajesh Kabra, Donita Atkins, Scott Koerber, Ahmed Hussein, Deepak Bhakta, Dhanunjaya Lakkireddy, Rakesh Gopinathannair Source Type: research