Ablation of ventricular tachycardia from right ventricular aneurysms in patients with arrhythmogenic cardiomyopathy guided by intracardiac echocardiography.

Background: The best approach for ablating ventricular tachycardia (VT) targeting right ventricular (RV) free wall aneurysms in arrhythmogenic right ventricular cardiomyopathy (ARVC) remains undefined.

Objective: We aimed to describe the technical approach, safety, and long-term efficacy of endocardial ablation of VT originating from RV free wall aneurysms in ARVC patients.

Methods: We identified ARVC patients with VT mapped to intracardiac echocardiography (ICE)-defined RV free wall aneurysms who underwent endocardial ablation targeting the aneurysmal area.

Considerations regarding safety with pulsed field ablation for atrial fibrillation.

The introduction of pulsed field ablation (PFA) in electrophysiology marks a significant advancement, promising efficacy comparable to thermal ablation methods while potentially providing safety advantages. Despite a generally favorable safety profile in human trials and postmarket registries, cautious evaluation of PFA's safety is essential. This review provides a comprehensive overview of key safety considerations as we discuss a myriad of considerations ranging from thermal effects, gaseous microbubble formation, muscle contractions, and proarrhythmia to procedural techniques.

Intraoperative pectoral nerve blocks during cardiac implantable electronic device procedures.

Background: Cardiac implantable electronic device (CIED) procedures can cause significant postoperative pain. Opioid use for postoperative pain is associated with risk of persistent use. The benefits of pectoral nerve (PECs) blocks have been established for other chest wall surgeries, but adoption in electrophysiology has been limited.

Atrial Fibrillation Substrate and Catheter Ablation Outcomes in MYBPC3- and MYH7-Mediated Hypertrophic Cardiomyopathy.

Background: The effects of disease-causing MYBPC3 or MYH7 genetic variants on atrial myopathy, atrial fibrillation (AF) clinical course, and catheter ablation efficacy remain unclear.

Objectives: The aim of this study was to characterize the atrial substrate of patients with MYBPC3- or MYH7-mediated hypertrophic cardiomyopathy (HCM) and its impact on catheter ablation outcomes.

Methods: A retrospective single-center study of patients with HCM who underwent genetic testing and catheter ablation for AF was performed.

Utilizing median and maximum QTc values improves prediction of breakthrough cardiac events in pediatric long QT syndrome.

Introduction: Although prior studies indicate that a QTc > 500 ms on a single baseline 12-lead electrocardiogram (ECG) is associated with significantly increased risk of arrhythmic events in long QT syndrome (LQTS), less is known about the risk of persistent QT prolongation. We sought to determine QTc persistence and its prognostic effect on breakthrough cardiac events (BCEs) among pediatric patients treated for LQTS.

Methods: We performed a retrospective analysis of 433 patients with LQTS evaluated, risk-stratified, and undergoing active guideline-based LQTS treatment between 1999 and 2019.

Arrhythmic manifestations and outcomes of definite and probable cardiac sarcoidosis.

Background: The 2014 Heart Rhythm Society consensus statement defines histological (definite) and clinical (probable) diagnostic categories of cardiac sarcoidosis (CS), but few studies have compared their arrhythmic phenotypes and outcomes.

Objective: The purpose of this study was to evaluate the electrophysiological/arrhythmic phenotype and outcomes of patients with definite and probable CS.

Methods: We analyzed the arrhythmic/electrophysiological phenotype in a single-center North American cohort of 388 patients (median age 56 years; 39% female, n = 151) diagnosed with definite (n = 58) or probable (n = 330) CS (2000-2022).

Predictors of nonpulmonary vein triggers for atrial fibrillation: A clinical risk score.

Background: Targeting non-pulmonary vein triggers (NPVTs) after pulmonary vein isolation may reduce atrial fibrillation (AF) recurrence. Isoproterenol infusion and cardioversion of spontaneous or induced AF can provoke NPVTs but typically require vasopressor support and increased procedural time.

Objective: The purpose of this study was to identify risk factors for the presence of NPVTs and create a risk score to identify higher-risk subgroups.

Identifying Origin of Nonpulmonary Vein Triggers Using 2 Stationary Linear Decapolar Catheters: A Novel Algorithm.

Background: Targeting nonpulmonary vein triggers (NPVTs) of atrial fibrillation (AF) after pulmonary vein isolation can be challenging. NPVTs are often single ectopic beats with a surface P-wave obscured by a QRS or T-wave.

Objectives: The goal of this study was to construct an algorithm to regionalize the site of origin of NPVTs using only intracardiac bipolar electrograms from 2 linear decapolar catheters positioned in the posterolateral right atrium (along the crista terminalis with the distal bipole pair in the superior vena cava) and in the proximal coronary sinus (CS).

Impact of Median Sternotomy on Safety and Efficacy of the Subcutaneous Implantable Cardioverter Defibrillator.

Background: Subcutaneous implantable cardioverter defibrillators (S-ICDs) are an attractive alternative to transvenous ICDs among those not requiring pacing. However, the risks of damage to the S-ICD electrode during sternotomy and adverse interactions with sternal wires remain unclear. We sought to determine the rates of damage to the S-ICD lead during sternotomy, inappropriate shocks from electrical noise due to interaction with sternal wires, and failure to terminate spontaneous or induced ventricular arrhythmias.

Complexity analysis of electrical activity during endocardial and epicardial biventricular mapping of ventricular fibrillation.

Background: Ventricular fibrillation (VF) is a lethal cardiac arrhythmia that is a significant cause of sudden cardiac death. Comprehensive studies of spatiotemporal characteristics of VF in situ are difficult to perform with current mapping systems and catheter technology.

Objective: The goal of this study was to develop a computational approach to characterize VF using a commercially available technology in a large animal model.

Effects of Pulsed Electric Fields on the Coronary Arteries in Swine.

Background: Previous animal studies have shown no significant vascular injury from pulsed electrical field (PEF) ablation. We sought to assess the effect of PEF on swine coronary arteries.

Methods: We performed intracoronary and epicardial (near the coronary artery) PEF ablations in swine pretreated with dual antiplatelet and antiarrhythmic therapy.

Novel insights into the substrate involved in maintenance of ventricular fibrillation: results from continuous multipolar mapping in a canine model.

Background: While the triggers for ventricular fibrillation (VF) are well-known, the substrate required for its maintenance remains elusive. We have previously demonstrated dynamic spatiotemporal changes across VF from electrical induction of VF to asystole. Those data suggested that VF drivers seemed to reside in the distal RV and LV.

Ventricular nanosecond pulsed electric field delivery using active fixation leads: a proof-of-concept preclinical study.

Background: Mid-myocardial ventricular arrhythmias are challenging to treat. Cardiac electroporation via pulsed electric fields (PEFs) offers significant promise. We therefore tested PEF delivery using screw-in pacemaker leads as proof-of-concept.