Rate-Dependent Pacemap Matching in Scar-Related Ventricular Tachycardia: Impact of "TR Fusion" Phenomenon.

Background: The impact of varying rates of pacemapping (PM) rates on QRS morphology and PM score matching in patients with scar-related ventricular tachycardia (VT) has not been systematically assessed.

Objectives: In this study, the authors sought to assess the variability in PM score matching at different pacing rates.

Methods: During substrate mapping for VT ablation, PM was performed at cycle lengths (CLs) of 600 ms, 500 ms, 400 ms, 300 ms, and VT CL.

Optimal cardiac rhythm during substrate mapping in scar-related ventricular tachycardia: Significance of wavefront direction on identifying critical sites.

Background: A rotational activation pattern (RAP) around the localized line of a conduction block often correlates with sites specific to the critical zones of ventricular tachycardia (VT). The wavefront direction during substrate mapping affects manifestation of the RAP and line of block.

Objective: The purpose of this study was to investigate the most optimal cardiac rhythm for identifying RAP and line of block in substrate mapping.

Incidence of cryoballoon expansion dislodgement during pulmonary vein isolation-An underappreciated frequent cause of incomplete isolation.

Background: Cryoballoon ablation for atrial fibrillation (AF) requires adequate contact between the pulmonary vein (PV) antrum and cryoballoon. The surge of intraballoon pressure during the initial phase of ablation may change the balloon's shape and compliance, resulting in balloon dislodgement and loss of PV occlusion. Without continuous monitoring, this phenomenon is often undetected but can be associated with incomplete PV isolation (PVI).

Balloon surface temperature-controlled ablation using a second-generation radiofrequency HotBalloon: an in vivo feasibility study.

Aims: The first-generation radiofrequency HotBalloon (RHB) is a size-adjustable single-shot device used in atrial fibrillation. The energy output is determined by its central temperature and not by its balloon surface temperature (BST), thus limiting its efficacy and safety. Therefore, a second-generation RHB was developed to monitor BST and enable BST-controlled ablation.

Stellate Ganglion Phototherapy Using Low-Level Laser: A Novel Rescue Therapy for Patients With Refractory Ventricular Arrhythmias.

Objectives: This study investigates the effect of stellate ganglion (SG) phototherapy in healthy participants and assesses its efficacy in suppressing electrical storm (ES) refractory to antiarrhythmic drugs and catheter ablation.

Background: Modulation of the autonomic nervous system has been shown to be an effective adjunctive therapy for ES.

Methods: Ten-minute SG phototherapy was performed twice weekly for 4 weeks in 20 healthy volunteers.

Upgrade of cardiac resynchronization therapy by utilizing additional His-bundle pacing in patients with inotrope-dependent end-stage heart failure: a case series.

Background: His-bundle pacing (HBP) alone may become an alternative to conventional cardiac resynchronization therapy (CRT) utilizing right ventricular apical (RVA) and left ventricular (LV) pacing (BiV) in selected patients, but the effects of CRT utilizing HBP and LV pacing (BiV) on cardiac resynchronization and heart failure (HF) are unclear.

Case Summary: We presented two patients with inotrope-dependent end-stage HF in whom the upgrade from conventional BiV to BiV pacing by the addition of a lead for HBP improved their HF status. Patient 1 was a 32-year-old man with lamin A/C cardiomyopathy, atrial fibrillation, and complete atrioventricular (AV) block.

Predictors of increase in pacing threshold after transcatheter pacing system implantation due to micro-dislodgement.

Background: Achieving a favorable pacing threshold with a Micra transcatheter pacing system (Micra-TPS) is needed to reduce battery depletion. In some cases, the threshold increases shortly after the device is implanted, and a higher pacing threshold may be required. This study aims to identify the causes and predictors of the increase in pacing threshold observed shortly after Micra-TPS implantation.

Lesion durability after antral pulmonary vein isolation using a radiofrequency hot balloon catheter.

Purpose: Antral pulmonary vein isolation (PVI) using a radiofrequency hot balloon catheter (RHB) is a feasible therapeutic option for treating atrial fibrillation (AF). Lesion durability after antral RHB-PVI remains unknown. This study aimed to evaluate lesion durability and the associations between procedural characteristics after antral RHB-PVI.

Predictors of Recurrence after Catheter Ablation of Paroxysmal Atrial Fibrillation in Different Follow-Up Periods.

Pulmonary vein (PV) reconnection is a major reason for recurrence after catheter ablation of paroxysmal atrial fibrillation (PAF). However, the timing of the recurrence varies between patients, and recurrence >1 year after ablation is not uncommon. We sought to elucidate the characteristics of atrial fibrillation (AF) that recurred in different follow-up periods.

Early clinical experience of radiofrequency catheter ablation using an audiovisual telesupport system.

Background: An audiovisual telesupport system that enables real-time audiovisual communications between 2 long-distance hospitals is one method of telemedicine. The usefulness and safety of radiofrequency catheter ablation (RFCA) using an audiovisual telesupport system has not been well established.

Objective: The purpose of this study was to evaluate the effectiveness and safety of RFCA using an audiovisual telesupport system.

Stepwise approach to induce infrequent premature ventricular complex using bolus isoproterenol and epinephrine infusion.

Background: Paucity of a premature ventricular complex (PVC) during ablation procedures may occur and be associated with a lower success rate. Isoproterenol (ISP) injections are commonly used to induce PVC; however, the induced tachycardia sometimes prevents the appearance of PVC. Epinephrine (EPI) administration may be an alternative strategy to induce PVC due to its smaller effect on heart rate (HR).

Initial Result of Antrum Pulmonary Vein Isolation Using the Radiofrequency Hot-Balloon Catheter With Single-Shot Technique.

Objectives: This study sought to determine the feasibility of a novel simplified ablation protocol targeting only the pulmonary vein antrum using the radiofrequency hot-balloon catheter in patients with paroxysmal atrial fibrillation.

Background: Radiofrequency hot-balloon (RHB) catheter has been recently introduced into clinical practice for pulmonary vein isolation (PVI). The authors hypothesized that a novel simplified ablation protocol targeting only the PV antrum with energy application for a longer time (single-shot technique) could be an alternative approach to achieve PVI, while avoiding unnecessary energy application at the PV ostium.

Iatrogenic aortic regurgitation after radiofrequency ablation of idiopathic ventricular arrhythmias originating from the aortic valvular region.

Background: Radiofrequency ablation at the aortic root has the potential risk of aortic regurgitation (AR).

Objective: This study investigated the incidence and clinical features of iatrogenic AR after catheter ablation of idiopathic ventricular arrhythmias originating from the aortic root.

Methods: We studied 45 consecutive patients with idiopathic ventricular arrhythmias originating from the aortic cusps (ACs; AC group; n = 32 [71%]) and papillary muscles (control group; n = 13 [29%]) who underwent ablation via a retrograde aortic approach and serial echocardiography before and within 24 hours after the ablation procedure.

Epicardial connection between the right-sided pulmonary venous carina and the right atrium in patients with atrial fibrillation: A possible mechanism for preclusion of pulmonary vein isolation without carina ablation.

Background: Ablation of the pulmonary venous carina is occasionally required for pulmonary vein isolation (PVI) despite its nonessential role in ipsilateral PVI from the anatomical (endocardial) viewpoint. Although the Bachmann bundle (BB) is a common and main interatrial band, local variations in small tongues of muscular fibers were frequently found in autopsy studies.

Objective: We sought to clarify the effect of the electrical conduction pattern from the right atrium (RA) to the left atrium (LA) during sinus rhythm on the necessity of performing right-sided pulmonary venous carina ablation to achieve PVI.

Idiopathic Ventricular Arrhythmias Originating From the Vicinity of the Communicating Vein of Cardiac Venous Systems at the Left Ventricular Summit.

Background: The communicating vein (CV) between the great cardiac vein and small cardiac venous systems passes between the aortic and pulmonary annulus and is located in close association with the left ventricular summit (summit CV).

Methods And Results: Thirty-one patients with idiopathic ventricular arrhythmias (VAs) underwent mapping of the left ventricular summit by using a 2F microcatheter introduced into the summit CV with coronary sinus venographic guidance. Of these, 14 patients were found to have summit-CV VAs.

Fascicular Ventricular Tachycardia Originating From Papillary Muscles: Purkinje Network Involvement in the Reentrant Circuit.

Background: Verapamil-sensitive fascicular ventricular tachycardia (FVT) has been demonstrated to be a reentrant mechanism using the Purkinje network as a part of its reentrant circuit. Although the papillary muscles (PMs) are implicated in arrhythmogenic structure, reentrant FVT originating from the PMs has not been well defined.

Methods And Results: We studied 13 patients in whom FVT was successfully eliminated by ablation at the posterior PMs (n=8; PPM-FVT) and anterior PMs (n=5; APM-FVT).

J Waves Are Associated With the Increased Occurrence of Life-Threatening Ventricular Tachyarrhythmia in Patients With Nonischemic Cardiomyopathy.

Introduction: Recent studies showed that J waves were associated with higher incidence of ventricular tachyarrhythmia (VT/VF) in patients with idiopathic ventricular fibrillation (VF) and myocardial infarction. We sought to assess the association between J waves and VT/VF in patients with nonischemic cardiomyopathy (NICM).

Methods And Results: We retrospectively enrolled 109 patients (79 men; mean age, 60 ± 15 years) with NICM who underwent implantable cardioverter defibrillator (ICD) implantation.

Successful coronary stenting in anomalous right coronary artery by using an inner catheter with mother and child technique under multislice CT guidance.

The ectopic location and unusual coronary course of the anomalous right coronary artery (RCA) from the left sinus of Valsalva makes percutaneous coronary intervention difficult. In this report, we describe a case of successful stent implantation in an anomalous RCA performed using a 4.5F inner catheter with a 6F guiding catheter used in the mother and child system under the guidance of multislice computed tomography.