Antitachycardia Pacing is More Effective When Delivered to the Left Bundle Branch Area Compared to the Right Ventricle in a Pre-clinical Model of Ischemic Ventricular Tachycardia.

Background: Anti-tachycardia pacing (ATP) delivered from implantable cardioverter defibrillators (ICDs) provides critically timed pacing pulses to terminate ventricular tachycardia (VT). Physiological pacing through left bundle branch area (LBBA) pacing has emerged as a clinically relevant alternative to induce synchronous activation of the ventricles. The main objective of this study was to compare the efficacy and safety of ATP delivered to an LBBA lead and a conventional RV lead.

Scoring Balloon Effects on Coronary Calcified Plaque: A Finite Element Analysis.

Background: Calcified plaques often adversely affect the clinical outcomes after percutaneous coronary intervention because of insufficient lesion expansion. Various pre-dilation balloons are available; however, the expansion effect of scoring balloons in the calcified plaque is unclear.

Aims: This study aimed to examine the effects of a scoring balloon on plaques compared with a noncompliant balloon.

Temporary Transvenous Pacemaker Lead-Induced Cardiac Perforation Incidentally Detected by Right Ventriculography Prior to Leadless Pacemaker Implantation.

Temporary transvenous pacemakers (TTPs) are lifesaving device in patients with hemodynamically unstable bradycardia, but are associated with serious complications, including right ventricular (RV) perforation. We present a case of a 91-year-old woman with complete atrioventricular block and bradycardia who received a TTP. After that, she underwent leadless pacemaker implantation.

AAV9-cBIN1 gene therapy rescues chronic heart failure due to ischemic cardiomyopathy in a canine model.

Background: Ischemic cardiomyopathy and resultant heart failure (HF) is a significant cause of morbidity and mortality worldwide. Downregulation of cardiac bridging integrator 1 (cBIN1), a membrane scaffolding protein responsible for organizing t-tubules and organizing the calcium handing apparatus, occurs in progressive HF. Therefore, gene therapy upregulating cBIN1 production may rescue failing muscle and clinical HF.

Inappropriate Shocks in Brugada Syndrome Patients With a Subcutaneous Implantable Cardioverter Defibrillator.

Background: This study aimed to compare inappropriate shock (IAS) rates between subcutaneous implantable cardioverter-defibrillator (S-ICD) and transvenous ICD (TV-ICD) in Brugada syndrome (BrS) patients and identify risk factors for IAS in S-ICD use.

Methods: We enrolled consecutive patients with BrS who underwent ICD implantation between 2013 and 2023. Data on clinical characteristics, S-ICD screening test data, and IAS occurrence were retrospectively analyzed.

Functional and Structural Remodeling as Atrial Fibrillation Progresses in a Persistent Atrial Fibrillation Canine Model.

Background: Contractile, electrical, and structural remodeling has been associated with atrial fibrillation (AF), but the progression of functional and structural changes as AF sustains has not been previously evaluated serially.

Objectives: Using a rapid-paced persistent AF canine model, the authors aimed to evaluate the structural and functional changes serially as AF progresses.

Methods: Serial electrophysiological studies in a chronic rapid-paced canine model (n = 19) prior to AF sustaining and repeated at 1, 3, and 6 months of sustained AF were conducted to measure changes in atrial conduction speed and direction.

Effective ablation settings that predict chronic scar after atrial ablation with HELIOSTAR™ multi-electrode radiofrequency balloon catheter.

Background: Radiofrequency balloon (RFB) ablation (HELIOSTAR™, Biosense Webster) has been developed to improve pulmonary vein ablation efficiency over traditional point-by-point RF ablation approaches. We aimed to find effective parameters for RFB ablation that result in chronic scar verified by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR).

Methods: A chronic canine model (n = 8) was used to ablate in the superior vena cava (SVC), the right superior and the left inferior pulmonary vein (RSPV and LIPV), and the left atrial appendage (LAA) with a circumferential ablation approach (RF energy was delivered to all electrodes simultaneously) for 20 s or 60 s.

Canine Model of Ischemia-Induced Ventricular Tachycardia.

Introduction: Despite advances in antiarrhythmia therapies, ventricular tachycardia (VT) is a leading cause of sudden cardiac death. Investigation into the characteristics and new treatments for this arrhythmia is required to improve outcomes and a reproducible model of VT would be useful in these endeavors. We therefore created a canine model of ischemia-induced VT.

Antitachycardia pacing at the His bundle is safer than conventional right ventricular antitachycardia pacing in a canine myocardial ischemic injury model.

Introduction: Antitachycardia pacing (ATP) is used to terminate ventricular tachycardia (VT) by delivering rapid, low energy pacing to the right ventricle (RV). Unfortunately, ATP is not effective against all VT episodes and can result in adverse outcomes, such as VT acceleration and degeneration into ventricular fibrillation (VF). Improving ATP is therefore desirable.

A canine model of chronic ischemic heart failure.

Preclinical large animal models of chronic heart failure (HF) are crucial to both understanding pathological remodeling and translating fundamental discoveries into novel therapeutics for HF. Canine models of ischemic cardiomyopathy are historically limited by either high early mortality or failure to develop chronic heart failure. Twenty-nine healthy adult dogs (30 ± 4 kg, 15/29 male) underwent thoracotomy followed by one of three types of left anterior descending (LAD) coronary artery ligation procedures: ( = 4) (simple LAD: proximal and distal LAD ligation); ( = 14) (simple LAD plus lateral wall including ligation of the distal first diagonal and proximal first obtuse marginal); and ( = 11) (total LAD devascularization or TLD: simple LAD plus ligation of proximal LAD branches to both the right and left ventricles).

Shorter distance between the esophagus and the left atrium is associated with higher rates of esophageal thermal injury after radiofrequency ablation.

Background: Esophageal thermal injury (ETI) is a known and potentially serious complication of catheter ablation for atrial fibrillation. We intended to evaluate the distance between the esophagus and the left atrium posterior wall (LAPW) and its association with esophageal thermal injury.

Methods: A retrospective analysis of 73 patients who underwent esophagogastroduodenoscopy (EGD) after LA radiofrequency catheter ablation for symptomatic atrial fibrillation and pre-ablation magnetic resonance imaging (MRI) was used to identify the minimum distance between the inner lumen of the esophagus and the ablated atrial endocardium (pre-ablation atrial esophageal distance; pre-AED) and occurrence of ETI.

Short-term natural course of esophageal thermal injury after ablation for atrial fibrillation.

Introduction: Esophageal injury is rare but potentially a devastating complication of atrial fibrillation (AF) ablation. The goal here was to provide insight into the short-term natural history of esophageal thermal injury (ETI) after radiofrequency catheter ablation (RFCA) for AFby esophagogastroduodenoscopy (EGD).

Methods: We screened patients who underwent RFCA for AF and EGD based on esophageal late gadolinium enhancement (LGE) in postablation magnetic resonance imaging.

Important factors in left atrial posterior wall isolation using 28-mm cryoballoon ablation for persistent atrial fibrillation-Block line or isolation area?

Introduction: Left atrial (LA) roof ablation using the cryoballoon technique, combined with pulmonary vein isolation (PVI), has been reported to be beneficial for ablation therapy in patients with persistent atrial fibrillation (AF). Left posterior wall ablation also results in improved patient outcomes. However, the contribution of these techniques to the success of cryoballoon ablation (CBA) treatment of AF is not known.

Novel use of a 3-dimensional mapping system in cryoablation of right-sided and septal accessory pathways: playback ablation.

Purpose: Despite recent advances in the treatment of eliminating accessory pathways (APs), catheter-induced mechanical block (bump) of APs has been reported to result in a less favorable outcome with high primary failure and recurrence rates. The real bump site cannot always be precisely reapproached under fluoroscopy so physicians can perform ablation to a location different from where the mechanical block was encountered. In this paper, we describe this novel use of a 3-dimensional (3D) mapping system (playback ablation) with a case series.

A relation between ablation area and outcome of ablation using 28-mm cryoballon ablation: Importance of carina region.

Introduction: Pulmonary vein isolation (PVI) with wide antral ablation leads to better outcomes in atrial fibrillation ablation therapy, but the ablation area is relatively small during cryoballoon ablation (CBA). The present study tested the hypothesis that wide ablation can lead to better outcomes in CBA.

Methods And Results: Ninety-six patients with atrial fibrillation were enrolled (paroxysmal 76%, 64.