Authors reply regarding "A-V-V-A response to single atrial premature depolarization in a narrow QRS tachycardia: What is the mechanism?".

We respond to a letter by Dr. A. Goyal.

Catheter ablation approach targeting epicardial connections to the right pulmonary vein antrum detected before pulmonary vein isolation.

Background: Epicardial connections from surrounding structures to the right pulmonary vein (PV) antrum impede PV isolation.

Objective: This study aimed to evaluate the efficacy of an ablation approach targeting epicardial connections for right PV isolation.

Methods: We prospectively enrolled 124 patients with atrial fibrillation undergoing initial PV isolation.

Characteristics of radiofrequency lesions in patients with symptomatic periesophageal vagal nerve injury after pulmonary vein isolation.

Background: Periesophageal vagal nerve injury (PNI) is an unpredictable and serious complication of atrial fibrillation (AF) ablation. We aimed to identify the factors associated with symptomatic PNI.

Methods: This study included 1391 patients who underwent ablation index-guided pulmonary vein isolation (PVI) using the CARTO system.

A randomized controlled trial of the size-adjustable cryoballoon vs conventional cryoballoon for paroxysmal atrial fibrillation: The CONTRAST-CRYO II trial rationale and design.

Background: Pulmonary vein isolation (PVI) with cryoballoon technology is a well-established therapy for treatment of atrial fibrillation (AF). Recently, a size-adjustable cryoballoon (POLARx FIT) that enables delivery in a standard 28-mm or an expanded 31-mm size was introduced.

Objective: The purpose of this study was to perform a randomized clinical trial to evaluate the safety and efficacy of this novel cryoballoon compared to the conventional cryoballoon.

Narrow QRS ectopy with concealed connections from a para-Hisian origin to the proximal left fascicles.

Introduction: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging.

Methods And Results: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms.

Conclusion: Some narrow QRS ectopy may originate from the vicinity of the conduction system, instead of the "true" conduction system, and have concealed connections from its origin to the conduction system.

The optimal slow pathway ablation site in atrioventricular nodal reentrant tachycardia cases with an inferiorly located His bundle.

Introduction: The optimal slow pathway (SP) ablation site in cases with an inferiorly located His bundle (HIS) remains unclear.

Methods And Results: In 45 patients with atrioventricular nodal reentrant tachycardia, the relationship between the HIS location and successful SP ablation site was assessed in electroanatomical maps. We assessed the location of the SP ablation site relative to the bottom of the coronary sinus ostium in the superior-to-inferior (SPSI), anterior-to-posterior (SPAP), and right-to-left (SPRL) directions.

[Surgical Treatment of the Perforation of the Right Ventricle and Diaphragm by a Permanent Pacing Lead:Report of a Case].

An 97-year-old woman was diagnosed with complete atrioventricular block and underwent pacemaker implantation( PMI). Three days after the PMI, computed tomography revealed cardiac perforation and migration of the lead to the abdominal cavity. Surgical procedure through median sternotomy was performed, and the penetrated lead was removed.

Characteristics of two different cryoballoon systems for treatment of paroxysmal atrial fibrillation: study protocol for a multicenter randomized controlled trial (CONTRAST-CRYO Trial).

Background: Single-shot pulmonary vein isolation (PVI) utilizing cryothermal energy is an effective and safe treatment for atrial fibrillation (AF) patients. A novel cryoballoon system, POLARx™, has been recently introduced. The aim of this study was to compare the efficacy, safety, and biophysical parameters of PVI between the novel cryoballoon system, POLARx™, and the standard cryoballoon system, Arctic Front Advance Pro™ (AFA-Pro), in patients with paroxysmal AF.

A-V-V-A response to single atrial premature depolarization in a narrow QRS tachycardia: What is the mechanism?

We present an atypical response to single atrial premature depolarization (APD) in a long RP' tachycardia. APD advanced the His-bundle potential immediately after it and resulted in a VA block; however, tachycardia persisted and consequently exhibited an A-V-V-A response. We propose the mechanism for an A-V-V-A response to APD in a long RP' tachycardia.

Incidence, distribution, and electrogram characteristics of endocardial-epicardial connections identified by ultra-high-resolution mapping during a left atrial posterior wall isolation of atrial fibrillation.

Purpose: The left atrial posterior wall (LAPW) can be a target for atrial fibrillation (AF) catheter ablation but is sometimes difficult to completely isolate due to the presence of endocardial-epicardial connections. We aimed to investigate the incidence and distribution of epicardial residual connections (epi-RCs) and the electrogram characteristics at epi-RC sites during an initial LAPW isolation.

Methods: We retrospectively studied 102 AF patients who underwent LAPW mapping before and after a first-pass linear ablation along the superior and inferior LAPW (pre-ablation and post-ablation maps) using an ultra-high-resolution mapping system (Rhythmia, Boston Scientific).

Ethanol infusion therapy for peri-mitral atrial tachycardia through the Marshall bundle with electrical irrelevance of left atrial appendage and mitral isthmus.

A 62-year-old man with a history of catheter ablation for atrial fibrillation and atrial tachycardia (AT) received a line of block of the mitral isthmus (MI) and electrical isolation of the left atrial appendage (LAA). Upon entrainment pacing, AT recurred and was diagnosed as peri-mitral AT (PMAT) with electrical irrelevance of MI, LAA, and left pulmonary vein, having a critical isthmus identified as Marshall bundle (MB). MB was then infused with ethanol, leading to the successful treatment of the PMAT.

Noncontact Charge Density Mapping-Guided Ablation of Persistent Atrial Fibrillation With a Multiple Trigger-Based Mechanism.

We present a case of radiofrequency catheter ablation of persistent atrial fibrillation (AF) with a trigger-based mechanism, guided by novel noncontact charge density mapping, which resulted in the simultaneous achievement of the termination of AF and complete elimination of multiple triggers that induced repeated recurrences of AF immediately after cardioversion. ().

Intra-septal radiofrequency ablation within the transseptal puncture hole targeting an interatrial connection during a bi-atrial tachycardia.

A 74-year-old man after multiple mitral valve surgeries underwent catheter ablation of a bi-atrial tachycardia (BiAT). Ultra-high resolution activation mapping exhibited a reentrant circuit propagating around the inferior to anterior mitral annulus and right atrial (RA) septum with two interatrial connections. At the transeptal puncture site, continuous fractionated electrograms were recorded during the BiAT, and entrainment pacing revealed a post-pacing interval similar to the tachycardia cycle length, which suggested that the interatrial conduction from the RA to the left atrium (LA) was located just at the transseptal puncture site.

Catheter ablation of the left-sided variant of right top pulmonary vein in a case with persistent left superior vena cava.

A 50-year-old woman underwent catheter ablation for atrial fibrillation. Preoperative computed tomography revealed a left-sided variant of the right top pulmonary vein (PV) and a persistent left superior vena cava. The right top PV was successfully isolated through a wide antral circumferential ablation line simultaneously with the right PVs.

Unusual QRS complexes associated with the simultaneous presence of a right-sided accessory pathway, fasciculoventricular pathway, and incomplete right bundle branch block.

Unlabelled: A 52-year-old man presented with delta waves on a body surface electrocardiogram, which suggested the presence of a right-sided accessory pathway (AP). Patients with right-sided APs generally have an rS pattern in leads V1-2, while he had an rS in lead V1 but an Rs in lead V2, which could not rule out the possibility of the presence of a septal AP or fasciculoventricular pathway (FVP). On the other hand, patients with septal APs or FVPs generally have a QS pattern in lead V1 instead of an rS pattern.

Provocation and Localization of Arrhythmogenic Triggers from Persistent Left Superior Vena Cava in Patients with Atrial Fibrillation.

Background: Although pulmonary vein isolation (PVI) is an established procedure for atrial fibrillation (AF), non-PV foci play a crucial role in AF recurrence. Persistent left superior vena cava (PLSVC) has been reported as critical non-PV foci. However, the effectiveness of provocation of AF triggers from PLSVC remains unclear.

Initial multicenter clinical experience with the first-generation endoscopic guided laser balloon in Japan.

Background: Isolation of the pulmonary veins (PVs) is the golden standard for atrial fibrillation (AF) ablation. To achieve a permanent PV isolation, the endoscopic guided HeartLight laser balloon system was invented. We analyzed the safety and efficacy of this laser balloon system.