A document by Matthew Hanson. Click on the document to view its contents.

Aims The treatment with the wearable cardioverter defibrillator (WCD) may protect against sudden cardiac death (SCD) as a bridging therapy until a cardioverter-defibrillator may be implanted. We analyzed in a multicenter setting a consecutive patient cohort wearing WCD to explore gender differences. Methods and results We analyzed 708 consecutive patients, 579 from whom were males and 129 females (age, 60.5±14 vs. 61.6±17 years old; p=0.44). All patients were divided into age quartiles for analysis. While the rate of ischemic cardiomyopathy (ICM) as a cause of prescription of WCD was significantly higher in males as compared to females (42.7% vs. 26.4%; p=0.001), females received it more frequently due to non-ischemic cardiomyopathy (NICM) (55.8% vs. 42.7%); p=0.009). The wear time of WCD was equivalent in both groups (21.1±4.3 hours/days in males vs. 21.5±4.4 hours/days in females; p=0.27; and 62.6±44.3 days in males vs. 56.5±39 days in females; p=0.15). Mortality was comparable in both groups at 2-year-follow-up (6.8% in males vs. 9.7% in females; p=0.55). Appropriate WCD shocks and the incidence of device implantations were similar in both groups (2.4% in males vs. 3.9% in females; p=0.07) (35.1% in males vs. 31.8% in females; p=0.37), respectively. In age quartile analysis, compliance was observed more in older patients as compared to adult patients (87.8% vs. 68.3%; p<0.001). Conclusion Compliance for wearing WCD was excellent regardless of gender. Furthermore, mortality and the incidence of device implantations were comparable in both groups. Appropriate WCD shocks tended to be higher in females as compared to males.

Introduction: The surface EKG of typical atrioventricular nodal reentrant tachycardia (AVNRT) shows simultaneous ventricular-atrial (RP) activation with pseudo R’ in V1 and typical heart rates ranging from 150-220/min. Slower rates are suspicious for junctional tachycardia (JT). However, occasionally we encounter typical AVNRT with slow ventricular rates. We describe a series of typical AVNRT cases with heart rates under 110/min. Methods: A total of 1972 patients with AVNRT who underwent slow pathway ablation were analyzed. Typical AVNRT was diagnosed when; 1) evidence of dual atrioventricular nodal conduction, 2) tachycardia initiation by atrial drive train with A-H-A response, 3) septal ventriculoatrial (VA) time < 70 ms, and 4) ventricular-atrial-ventricular (V-A-V) response to ventricular overdrive (VOD) pacing with post pacing interval-tachycardia cycle length (PPI-TCL) > 115ms. JT was excluded by either termination or advancement of tachycardia by atrial extrastimuli (AES) or atrial overdrive (AOD) pacing. Results: We found 11 patients (Age 20-78 years old, 6 female) who met the above-mentioned criteria. The TCL ranged from 560ms to 782ms. Except for one patient showing tachycardia termination, all patients demonstrated a V-A-V response and PPI-TCL over 115ms with VOD. AES or AOD pacing successfully excluded JT by either advancing the tachycardia in 10 patients or by tachycardia termination in one patient. Slow pathway was successfully ablated, and tachycardia was not inducible in all patients. Conclusions: This case series describes patients with typical AVNRT with slow ventricular rate (less than 110/min) who may mimic JT. We emphasize the importance of using pacing maneuvers to exclude JT.

Atrial fibrillation (AF) is the most common atrial arrhythmia and is subcategorized into numerous clinical phenotypes. Given its heterogeneity, investigations into the genetic mechanisms underlying AF have been pursued in recent decades, with predominant analyses focusing on early onset or lone AF. Linkage analyses, genome wide association studies (GWAS), and single gene analyses have led to the identification of rare and common genetic variants associated with AF risk. Significant overlap with genetic variants implicated in dilated cardiomyopathy syndromes, including truncating variants of the sarcomere protein titin, have been identified through these analyses, in addition to other genes associated with cardiac structure and function. Despite this, widespread utilization of genetic testing in AF remains hindered by the unclear impact of genetic risk identification on clinical outcomes and the high prevalence of variants of unknown significance (VUS). However, genetic testing is a reasonable option for patients with early onset AF and in those with significant family history of arrhythmia. While many knowledge gaps remain, emerging data support genotyping to inform selection of AF therapeutics. In this review we highlight the current understanding of the complex genetic basis of AF and explore the overlap of AF with inherited cardiomyopathy syndromes. We propose a set of criteria for clinical genetic testing in AF patients and outline future steps for the integration of genetics into AF care.

What is Different About Pulsed Field Ablation … Everything?David E. Haines, MDBeaumont Health System, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan, USAFunding: NoneDisclosures: Dr. Haines is a consultant for Ablacon, Inc., Affera, Inc., Biosense Webster, Inc., Boston Scientific Corporation, Inc., Medtronic, Inc., and Philips Healthcare, Inc. He has equity interest in Ablacon, Inc. and Affera, Inc.Corresponding author:David E. Haines, MD Director, Heart Rhythm Center Professor, Cardiovascular Medicine Oakland University William Beaumont School of Medicine 3601 West 13 Mile Road Royal Oak, MI 48073 248-898-4176 [email protected] the time of early preclinical reports of the efficacy, speed and safety of pulsed field ablation (PFA), the interventional electrophysiology community has been waiting in anxious anticipation for its clinical approval and release. As most people actively engaged in interventional electrophysiology know, PFA is the technology that creates myocardial lesions with trains of very high voltage pulses that are nanoseconds or microseconds in duration.1 This form of ablation is nonthermal, and cell injury/death is created by electroporation of the organelles and sarcolemmal membrane, with cell death occurring via apoptosis as well as other mechanisms.2 Because myocardial ablation is the result of an electrical field effect, electrode-tissue proximity is important but contact force is not. The physiological effect of acute PFA is striking in that there is immediate loss of electrical signal so that acute pulmonary vein isolation is achieved from a single shot catheter in under one second (figure 1). Preclinical animal studies have demonstrated effective chronic lesions that have been reliably transmural for atrial ablations.3 But the most compelling aspect of PFA is the apparent tissue selectivity of this energy form. At doses sufficient to create reliable transmural lesions in animals, there is little or no discernable injury to the esophagus, phrenic nerves, coronary arteries or distal pulmonary veins, in contrast to ablation with thermal techniques such as radiofrequency or cryoballoon ablation, where thermal collateral injury to contiguous structures can lead to substantial morbidity and death.4,5So, what is the catch? Is there any downside to PFA compared to other ablation technologies? The answer is that we do not know. Despite a substantial body of preclinical experience published to date, clinical outcomes with PFA are just starting to be reported. In this issue of theJournal , Neven et al describe the acute pathological effects of PFA in a swine model over the first 60 minutes and compare them to findings from chronic animals at 3 weeks and 3 months.6 For their study, they mostly employed a suction electrode for epicardial delivery (some lesions created with a circular catheter under blood) and delivered a single unipolar cathodal pulse of mostly 200 J (some dose ranging performed with chronic lesions between 30 – 200 J) at various sites on the right and left ventricles. Pathology on acute specimens was examined 0 to 60 minutes post ablation, and chronic specimens were examined after 3 weeks and 3 months. They reported that acute lesions showed contraction band necrosis and interstitial edema, and at >/= 3 weeks, there was sharply demarcated connective tissue that evolved into scar.What new insights have we gained from the present study that we can now apply to the burgeoning field of clinical PFA? Unfortunately, despite considerable effort put forth by these investigators, their results are not generalizable to the wider field of PFA. No study reporting outcomes using one proprietary PFA system will be necessarily applicable to results from a competing proprietary system. The field of catheter ablation has become accustomed to interchangeability of one RF generator or catheter for another. That is because the thermodynamics of electrical resistive heating of tissue is predictable, and there are limited operator parameters (power, time, contact force) and design parameters (electrode size, convective cooling) that affect tissue heating. The biological effects of hyperthermia are straightforward and reproducible; thus, it is possible for scientists and clinicians to compare experiences from one proprietary RFA system to another and draw some generalizable conclusions. 7 Not so with PFA. To paraphrase an old saying, “When you’ve seen one PFA system, you’ve seenone PFA system.” The operator-controlled parameters are familiar (energy level, catheter-tissue position), but the design parameter variations are dizzying and most importantly unknown to us . A precedent was set early in the development of this field that the PFA waveform was proprietary, and that the commercialized product was a “black box”. A few of the parameters that can be modulated by the manufacturer include pulse amplitude, pulse duration, unipolar/bipolar, monophasic/biphasic, interpulse delay, interphase delay, pulse train number, pulse train duration and more. For example, the waveform used by Neven et al. was a milliseconds duration, monophasic damped sine wave generated by an external defibrillator (Lifepak 9, Physio-Control, Inc; Redmond, WA) and delivered in a unipolar cathodal fashion to an indifferent dispersive skin electrode. In contrast, most PFA systems deliver pulses are nanoseconds to microseconds in duration with a range of variation of the other parameters listed above (figure 2). Thus, the outcomes from ablation with a proprietary PFA system cannot and should not be extrapolated to different proprietary systems that may have dramatically different waveforms that result in different procedural outcomes.One of the major unanswered questions in the field of PFA is what is the time course of clinical effect after energy delivery? The hope and anticipation has been that lesions created by PFA will be more durable than those created with thermal ablation techniques (RFA or cryoablation). A dramatic features of catheter ablation with PFA is that disappearance of the local electrograms is seen immediately after pulse delivery (figure 1). Unfortunately, this does not necessarily indicate that a permanent lesion has been created. Beyond the border of irreversible electroporation there is a penumbra of reversible electroporation manifested by loss of the electrical signal but maintenance of viability. In the heart, this has been described pathologically as a rim of tissue with enhanced with hematoxylin and eosin staining, and maintenance of mitochondrial activity as delineated by cytochrome C oxidase staining.8 Thus, the acute end point of conduction block and loss of local electrogram signal employed in RF ablation does not indicate that a permanent lesion has been made with PFA. With myocardial ablation, the extent of reversible electroporation beyond the border of permanent injury has not been fully characterized, nor has the time course of recovery of normal function. There are many anecdotal reports of pulmonary vein reconnection after acute PVI with PFA in patients with atrial fibrillation. Unfortunately, the present study did not report mapping data and compare the extent of acute physiological effect to the acute pathological lesions.Therefore, a challenge for operators performing PFA is that acute electrogram voltage mapping cannot be used as a metric to assess therapeutic effect. The strategy adopted for PVI with PFA is to deliver a very large ablation dose, since injury to collateral structures is rare.9 The larger the energy delivery, the more likely it will be that permanent block is achieved. One experienced operator concluded “Go big or go home”. Once again, the pulse wave morphology, pulse width and pulse train number are proprietary features of the system that are preselected. The operator can choose different pulse amplitudes, but in almost all cases the maximum setting is selected. Is there such a thing as too much energy delivery with PFA? In preclinical studies, very high energy delivery has been associated with large volume microbubble production and evidence of thermal effects (charring) at the electrode-tissue interface. Creating a large uncontrolled lesion may be appropriate for a narrowly defined anatomical target like the pulmonary vein antrum but may not be appropriate for targeting other arrhythmogenic substrates because of concern about excessive injury to the surrounding myocardium. The consequences of very high PFA energy delivery in the clinical setting are unknown but most experts believe that there should be an upper safe limit established for each unique PFA system. So, the manufacturers will decide the dosing that the clinician will use. Will the recommended dose be safe and effective for all patients going forward? Time will tell. Ideally, we should have a method to assess myocardial viability after PFA prior to removing catheters from the heart, so that touch up ablations with improved catheter-tissue proximity can be performed. With RFA, promising technologies like real time magnetic resonance imaging,10 near field ultrasound imaging11 and NADH fluorescence12 have been explored, but their utility in assessing acute PFA lesions is unknown.The era of PFA is exciting and full of promise, but there are many unanswered questions that remain. As we gain more clinical experience with PFA, the benefits and limitations of the various commercial systems will become more obvious. Because of its speed and safety, PFA is likely to become the dominant mode of ablation for PVI, but we need to move forward in this field cautiously with recognition that all of the consequences of this ablation mode are still unknown.References:Verma A, Asivatham SJ, Deneke T, Castellvi Q, Neal RE. Primer on pulsed electrical field ablation: understanding the benefits and limitations. Circulation Arrhythm Electrophysiol. 2021; 14: e010086. doi.org/10.1161/CIRCEP.121.010086.Napotnik TB, Polajzer T, Miklavcic D. Cell death due to electroporation – A review. Bioielectrochemistry. 2021; 141:107871.Stewart MT, Haines DE, Verma A, Kirchhof N, Barka N, Grassl E, Howard B. Intracardiac pulsed field ablation: Proof of feasibility in a chronic porcine model. Heart Rhythm. 2019; 16:754-764. doi: 10.1016/j.hrthm.2018.10.030.Bradley CJ, Haines DE. Pulsed field ablation for pulmonary vein isolation in the treatment of atrial fibrillation. J Cardiovasc Electrophysiol. 2020 Aug;31(8):2136-2147. doi: 10.1111/jce.14414.Koruth J.S., Kuroki K., Kawamura I., et. al.: Pulsed field ablation vs radiofrequency ablation: esophageal injury in a novel porcine model. Circ Arrhythm Electrophysiol 2020; 13:Neven K, van Driel VJHM, Vink A, du Pre BC, van Wessel H, Futing A, Doevendans PA, Wittkampf FHM, van Es R. Characteristics and time course of acute and chronic myocardial lesion formation after electroporation ablation in the porcine model. J Cardiovasc Electrophysiol. 2022 (in press).Haines DE. Biophysics and Pathophysiology of Radiofrequency Lesion Formation. In: Catheter Ablation of Cardiac Arrhythmias, 4th Edition. Huang SKS, Miller JM, editors. Philadelphia, PA: Elsevier Saunders Publishing, 2020.Nakagawa H, Castellvi, Neal R, Girouard S, Kuroda S, Hussein AA, Saliba WI, Wazni OM. Histological characterization of reversible and irreversible ventricular lesion boundaries produced by pulsed field ablation. Heart Rhythm 2021; 18: S151-S152. doi: 0.1016/j.hrthm.2021.06.386Reddy VY, Neuzil P, Koruth JS, Petru J, Funosako M, Cochet H, Sediva L, Chovanec M, Dukkipati SR, Jais P. Pulsed field ablation for pulmonary vein isolation in atrial fibrillation. J Am Coll Cardiol 2019; 74: pp. 315-326. doi: 10.1016/j.jacc.2019.04.021.Mukherjee RK, Roujol S, Chubb H, Harrison J, Williams S, Whitaker J, O’Neill L, Silberbauer J, Neji R, Schneider R, Pohl T, Lloyd T, O’Neill M, Razavi R. Epicardial electroanatomical mapping, radiofrequency ablation, and lesion imaging in the porcine left ventricle under real-time magnetic resonance imaging guidance-an in vivo feasibility study. Europace. 2018 Sep 1;20(FI2):f254-f262. doi: 10.1093/europace/eux341.Haines DE, Wright M, Harks E, Deladi S, Fokkenrood S, Brink R, Belt H, Kolen AF, Mihajlovic N, Zuo F, Rankin D, Stoffregen W, Cockayne D, Cefalu J. Near-Field Ultrasound Imaging During Radiofrequency Catheter Ablation: Tissue Thickness and Epicardial Wall Visualization and Assessment of Radiofrequency Ablation Lesion Formation and Depth. Circ Arrhythm Electrophysiol. 2017 Dec;10(12):e005295. doi: 10.1161/CIRCEP.117.005295.Swift L, Gil DA, Jaimes R 3rd, Kay M, Mercader M, Sarvazyan N. Visualization of epicardial cryoablation lesions using endogenous tissue fluorescence. Circ Arrhythm Electrophysiol. 2014 Oct;7(5):929-37. doi: 10.1161/CIRCEP.114.001750.Figures:Figure 1 – A circular ablation catheter is positioned in the right superior pulmonary vein antrum (PV 1 thorugh 9) and high frequency near field pulmonary vein potentials were recorded. Immediately after delivery of a PFA pulse, the pulmonary vein potentials are eliminated.Figure 2 – A. Irreversible electroporation waveform similar to that employed by Neven et al. from a Lifepak 9 defibrillator (Physio-control Service Manual No. 803763-06, Physio-control, Redmond, WA). B. Representative waveform from a pulsed field ablation generator using a train of biphasic microsecond duration pulses.

Although uncommonly encountered, dual atrioventricular nodal non-reentrant tachycardia (DAVNNRT) is a well described arrhythmia that can manifest in patients with dual atrioventricular nodal pathways physiology. This arrhythmia is characterized on ECG by a single P wave followed by two conducted QRS complexes, and on intracardiac EGMs by a single atrial electrogram followed by two separate His deflections and ventricular electrograms. Our case demonstrates a rare case of “triple atrioventricular non-reentrant tachycardia” in which a patient was found to have 3 distinct AV nodal pathways and multiple “triple fire responses”, both on surface ECG and intracardiac electrograms.

Transseptal left atrial catheterization is routinely used for many common catheter-based interventions. Tools for transseptal catheterization have advanced over the recent years. Such tools include imaging advances with intracardiac echocardiology as well as an array of needles, wires, and dilators to achieve transseptal access with greater ease and safety. This review will discuss the contemporary tools for transseptal catheterization and guidance for difficult cases.

Background: Infection remains a major complication of cardiac implantable electronic devices (CIEDs) and can lead to significant morbidity and mortality. Extrathoracic devices that avoid epicardial or transvenous leads, such as the subcutaneous implantable cardioverter-defibrillator (S-ICD), can reduce the risk of serious infection-related complications, such as bloodstream infection and infective endocarditis. While the 2017 AHA/ACC/HRS guidelines include recommendations for S-ICD use for patients at high risk of infection, currently, there are no clinical trial data that address best practices for the prevention of S-ICD infections. Therefore, an expert panel was convened to develop consensus on these topics. Methods: An expert process mapping methodology was used to achieve consensus on the appropriate steps to minimize or prevent S-ICD infections. Two face-to-face meetings of high-volume S-ICD implanters and an infectious diseases specialist, with expertise on cardiovascular implantable electronic device infections, were conducted to develop consensus on useful strategies pre-, peri-, and post-implant to reduce S-ICD infection risk. Results: Expert panel consensus of recommended steps for patient preparation, S-ICD implantation, and post-operative management were developed to provide guidance in individual patient management. Conclusion: Achieving expert panel consensus by process mapping methodology for S-ICD infection prevention was attainable, and the results should be helpful to clinicians in adopting interventions to minimize risks of S-ICD infection.

In the context of atrial fibrillation (AF), traditional clinical practices have thus far fallen short in several domains such as identifying patients at risk of incident AF or patients with concomitant undetected paroxysmal AF. Novel approaches leveraging artificial intelligence have the potential to provide new tools to deal with some of these old problems. In this review we focus on the roles of artificial intelligence-enabled ECG pertaining to AF, potential roles of deep learning (DL) models in the context of current knowledge gaps, as well as limitations of these models. One key area where DL models can translate to better patient outcomes is through automated ECG interpretation. Further, we overview some of the challenges facing AF screening and the harms and benefits of screening. In this context, a unique model was developed to detect underlying hidden AF from sinus rhythm and is discussed in detail with its potential uses. Knowledge gaps also remain regarding the best ways to monitor patients with ESUS and who would benefit most from oral anticoagulation. The AI-enabled AF model is one potential way to tackle this complex problem as it could be used to identify a subset of high-risk ESUS patients likely to benefit from empirical oral anticoagulation. Role of DL models assessing AF burden from long duration ECG data is also discussed as a way of guiding management. There is a trend towards the use of consumer-grade wristbands and watches to detect AF from photoplethysmography data. However, ECG currently remains the gold standard to detect arrythmias including AF. Lastly, role of adequate external validation of the models and clinical trials to study true performance is discussed.

Background: Implantable cardioverter defibrillators (ICD) are indicated for primary and secondary prevention of sudden cardiac arrest. Despite enhancements in design and technologies, the ICD lead is the most vulnerable component of the ICD system and failure of ICD leads remains a significant clinical problem. A novel, small diameter, lumenless, catheter delivered, defibrillator lead was developed with the aim to improve long term reliability. Methods and Results: The Lead Evaluation for Defibrillation and Reliability (LEADR) study is a multi-center, single-arm, Bayesian, adaptive design, pre-market interventional pivotal clinical study. Up to 60 study sites from around the world will participate in the study. Patients indicated for a de novo ICD will undergo defibrillation testing at implantation and clinical assessments at baseline, implant, pre-hospital discharge, 3 months, 6 months, and every 6 months thereafter until official study closure. Patients will participate for a minimum of 18 months to approximately 3 years. Fracture-free survival will be evaluated using a Bayesian statistical method that incorporates both virtual patient data (combination of bench testing to failure with in-vivo use condition data) with clinical patients. The clinical subject sample size will be determined using decision rules for number of subject enrollments and follow-up time based upon the observed number of fractures at certain time points in the study. The adaptive study design will therefore result in a minimum of 500 and a maximum of 900 patients enrolled. Conclusion: The LEADR Clinical Study was designed to efficiently provide evidence for short- and long-term safety and efficacy of a novel lead design using Bayesian methods including a novel virtual patient approach.

Subcutaneous implantable cardioverter defibrillators (S-ICDs) are currently indicated for patients who meet ICD implantation criteria for the prevention of sudden cardiac death (SCD). In December 2020, a unique cardiac implantable electronic device (CIED) situation arose as both the S-ICD generator and electrode were under a device advisory. We would recommend all future CIED implantation guidelines receive a caveat regarding checking current CIED advisories, in order to avoid future similar scenarios.

A document by Emily Zeitler. Click on the document to view its contents.

Leadless Pacemaker Implantation after Lead Extraction for Cardiac Implanted Electronic Device InfectionJamia Kowal, D.O.andGeorge H. Crossley, M.D., F.H.R.S, F.A.C.C.

Background: Insertable cardiac monitors (ICMs) are essential for ambulatory arrhythmia diagnosis. However, definitive diagnoses still require time-consuming, manual adjudication of electrograms (EGMs). Objective: To evaluate the clinical impact of selecting only key EGMs for review. Methods: Retrospective analyses of randomly selected Abbott Confirm Rx TM devices with ≥90 days of remote transmission history was performed, with each EGM adjudicated as true or false positive (TP, FP). For each device, up to 3 “key EGMs” per arrhythmia type per day were prioritized for review based on ventricular rate and episode duration. The reduction in EGMs and TP days (patient-days with at least 1 TP EGM), and any diagnostic delay (from the first TP), were calculated vs. reviewing all EGMs. Results: In 1,000 ICMs over a median duration of 8.1 months, at least one atrial fibrillation (AF), tachycardia, bradycardia, or pause EGM was transmitted by 424, 343, 190, and 325 devices, respectively, with a total of 95716 EGMs. Approximately 90% of episodes were contributed by 25% of patients. Key EGM selection reduced EGM review burden by 43%, 66%, 77%, and 50% (55% overall), while reducing TP days by 0.8%, 2.1%, 0.2%, and 0.0%, respectively. Despite reviewing fewer EGMs, 99% of devices with a TP EGM were ultimately diagnosed on the same day vs. reviewing all EGMs. Conclusions: Key EGM selection reduced the EGM review substantially with no delay-to-diagnosis in 99% of patients exhibiting true arrhythmias. Implementing these rules in the Abbott patient care network may accelerate clinical workflow without compromising diagnostic timelines.

Introduction: The extravascular ICD (EV ICD) system with substernal lead placement is a novel non-transvenous alternative to current commercially available ICD systems. The EV ICD provides defibrillation and pacing therapies without the potential long-term complications of endovascular lead placement. Methods: This paper summarizes the development of the EV ICD, including the pre-clinical and clinical evaluations that have contributed to system and procedural refinements to date. Results: Extensive pre-clinical research evaluations and 4 human clinical studies with >140 combined acute and chronic implants have enabled the development and refinement of the EV ICD system, currently in worldwide pivotal study. Conclusion: The EV ICD may represent a clinically valuable solution in protecting patients from sudden cardiac death while avoiding the long-term consequences of transvenous hardware. The EV ICD offers advantages over transvenous and subcutaneous systems by avoiding placement in the heart and vasculature; relative to subcutaneous systems, EV ICD requires less energy for defibrillation, enabling a smaller device, and provides pacing features such as anti-tachycardia and asystole pacing in a single system.

Title: Gradual prolongation of PR interval followed by a pause. What’s the mechanism?

Objective: The implantation depth and membranous septum (MS) length are established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV. Methods and results: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoint was in-hospital new-onset CD (new-onset left bundle branch block or new permanent pacemaker implantation). New-onset CD developed in 37 patients (21.9%). Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 – 31.5, p = 0.0407) and implantation depth – MS length (OR: 1.30, 95% CI: 1.12 – 1.51, p = 0.0005) as the predictors of new-onset CD within BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted deeper in BAV than TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients having BAV (22.3% vs 13.9%, p = 0.0458). Conclusion: The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. High implantation technique could be considered to avoid new-onset CD in BAV anatomy.

Title:Taking the “Pulse” of Pulsed Field Ablation: Real-World Experience