Hitoshi Hachiya

Clinical implications of reconnection between the left atrium and isolated pulmonary veins provoked by adenosine triphosphate after extensive encircling pulmonary vein isolation.

Introduction: Dormant pulmonary vein (PV) conduction can be provoked by adenosine triphosphate (ATP) after extensive encircling pulmonary vein isolation (EEPVI). However, the clinical implication of reconnection between the left atrium (LA) and isolated PVs provoked by ATP (ATP‐reconnection) remains unknown.

How to Diagnose, Locate, and Ablate Coronary Cusp Ventricular Tachycardia

Catheter Ablation of LVOT VT from a Coronary Cusp. Introduction: Although radiofrequency energy usually is applied to the most favorable endocardial site in patients with outflow tract ventricular tachycardia, there are still some patients in whom the tachycardia can be ablated only from an epicardial site. We established the characteristics and technique of catheter ablation from both the left and right coronary cusps to cure left ventricular outflow tract ventricular tachycardia.

Electrocardiographic Characteristics of Left Ventricular Outflow Tract Tachycardia

Catheter ablation of idiopathic left ventricular outflow tract tachycardia (LVOT‐VT) is rare because a safe ablation technique at this site has not been described, and serious complications may occur. This study compared the QRS morphology of LVOT‐VT with that of idiopathic right ventricular outflow tract tachycardia. A comparison was made between the electrocardiographic characteristics of LVOT‐VT originating from the supravalvular region of a coronary cusp (Supra‐Ao group) with those of LVOT‐VT originating from the infravalvular endocardial region of a coronary cusp of the aortic valve within the LV (Infra‐Ao group). After precise mapping of the right ventricle, left ventricle, pulmonary artery, coronary cusps, and proximal portion of the anterior interventricular vein, there were 17 patients in whom VT was thought to be located at the LVOT by both activation and pace mapping. They were divided between a Supra‐Ao group (n = 8), and an Infra‐Ao group (n = 9). Analysis of the 12‐lead electrocardiogram (ECG) revealed an S wave in lead I in all 17 patients. A precordial R wave transition was also observed at V1 or V2 in 16 patients (94%). In 7 of 8 patients (88%) with Supra‐Ao LVOT‐VT, no S wave was observed in either V5 or V6. In contrast, an Rs pattern was observed in both V5 and V6, or in V6 only, in 100% of the patients with Infra‐Ao LVOT‐VT. A LVOT‐VT should be suspected when the ECG shows an S wave in lead I and an R/S ratio greater than 1 in lead V1 or V2, versus a coronary cusp location if there is no S wave in either lead V5 or V6.

Electrocardiographic Characteristics of Repetitive Monomorphic Right Ventricular Tachycardia Originating Near the His‐Bundle

Introduction: Most idiopathic nonreentrant ventricular tachycardia (VT) and ventricular premature contractions (VPCs) arise from the right or left ventricular outflow tract (OT). However, some right ventricular (RV) VT/VPCs originate near the His‐bundle region. The aim of this study was to investigate ECG characteristics of VT/VPCs originating near the His‐bundle in comparison with right ventricular outflow tract (RVOT)‐VT/VPCs.

Chronic Hemodynamic Effects After Radiofrequency Catheter Ablation of Frequent Monomorphic Ventricular Premature Beats

Introduction: Radiofrequency catheter ablation (RFCA) of severely symptomatic monomorphic ventricular premature beats (VPBs) is reported to be a safe and effective treatment option. However, the chronic hemodynamic effects of these VPBs have not been precisely evaluated.

Prospective Evaluation of Bilateral Diaphragmatic Electromyograms During Cryoballoon Ablation of Atrial Fibrillation.

Left phrenic nerve injury (PNI) can occur during cryoballoon ablation of the left pulmonary veins (PVs). This study aimed to evaluate the feasibility of monitoring the bilateral phrenic nerve function during cryoballoon ablation of atrial fibrillation (AF).

Pulmonary Vein Isolation Using a Second-Generation Cryoballoon in Patients With Paroxysmal Atrial Fibrillation: One-Year Outcome Using a Single Big-Balloon 3-Minute Freeze Technique.

The second‐generation cryoballoon (CB) has been recently introduced into clinical use for pulmonary vein isolation (PVI). Data on the feasibility, long‐term outcome, and optimal freeze cycle are still limited. We assessed the 1‐year clinical outcome after second‐generation CB ablation with single 3‐minute freeze techniques, and clinical variables associated with AF recurrence.

Role of arrhythmogenic superior vena cava on atrial fibrillation.

It is well known that superior vena cava (SVC) is one of the important non‐pulmonary vein (PV) foci of atrial fibrillation (AF). However, little is known regarding the role of arrhythmogenic SVC in AF.

Adenosine Triphosphate Test After Cryothermal Pulmonary Vein Isolation: Creating Contiguous Lesions Is Essential for Eliminating Dormant Conduction

Adenosine triphosphate (ATP) testing reveals dormant pulmonary vein (PV) conduction after electrical PV isolation (PVI). This study aimed to evaluate the incidence of latent PV conduction after cryothermal PVI.

Utility of Distinctive Local Electrogram Pattern and Aortographic Anatomical Position in Catheter Manipulation at Coronary Cusps

Distinctive Electrogram and Aortography of Coronary Cusp.u2002Background: The coronary cusps have recently become target sites for radiofrequency catheter ablation of both outflow tract ventricular arrhythmias originating near the coronary cusps (CC‐VA) and atrial tachyarrhythmias such as focal atrial tachycardia originating near the noncoronary cusp (NCC‐AT). However, the relation between local electrograms recorded at each CC during sinus rhythm and their anatomical position as assessed by aortography has not yet been systematically described.