Takashi Uchiyama

Impact of atrial fibrillation termination on clinical outcome after ablation in relation to the duration of persistent atrial fibrillation.

Background: Whether procedural termination of persistent atrial fibrillation (AF) is necessary for optimal clinical efficacy still remains controversial. We sought to characterize the patients with persistent AF in whom procedural AF termination impacted an improved clinical outcome after ablation.

Wide QRS tachycardia: what is the mechanism?

A 47-year-old woman with regular wide QRS tachycardia without any structural heart disease was referred to our center for catheter ablation. The tachycardia was terminated by direct current cardioversion. A 12-lead electrocardiogram showed intraventricular conduction delay in sinus rhythm (Fig. 1A). The morphology of QRS during the tachycardia (Fig. 1B) was similar to that in sinus rhythm. Baseline electrophysiological test demonstrated a long HV interval (102 milliseconds) (Fig. 2A) and dual atrioventricular nodal physiology with antegrade pathway. The inducibility of the tachycardia was very low by programmed stimulation. Finally, the tachycardia with a cycle length of 310 milliseconds could be induced (Fig. 2B) by atrial double extrastimuli

Where Is the Initiation of Atrial Fibrillation

A 67-year-old woman with drug-resistant paroxysmal atrial fibrillation (AF) without any structural heart disease was referred to our center for catheter ablation. The procedure was performed under conscious sedation, and the starting rhythm was sinus rhythm. A 14-pole mapping catheter (Irvine Biomedical Inc., Irvine, CA, USA) was inserted through the right jugular vein and positioned in the coronary sinus. A decapolar circular mapping catheter (Lasso, Biosense Webster, Diamond Bar, CA, USA) was advanced in the left atrium through a transseptal hole,

Impact of Preceded Pharmacological Cardioversion on Ablation Strategy of Persistent Atrial Fibrillation

Purpose: This study was aimed to investigate the ablation strategy for persistent atrial fibrillation (PerAF) which pharmacological cardioversion (PC) was tried before catheter ablation (CA). Methods: This retrospective study included consecutive 80 patients (63±9 years, 71 male) who underwent CA for PerAF (duration: 42±55 months). When sinus rhythm (SR) was maintained at the beginning of the procedure, extensive encircling pulmonary vein isolation (EEPVI), superior vena cava isolation (SVCI), and cavotricuspid isthmus block (CTIB) were done. If AF persisted after completion of EEPVI, atrial substrate ablation (ASA) was added until AF termination as its endpoint. Results: Thirty-nine patients for which PC was attempted were divided into 18 patients (46%, Group A) restored to SR, and 21 patients (54%, Group B) PC was failed. CA was performed during AF in 7, 19 patients of Group A, B (39 vs. 90%, p=0.001). Among these 7 patients with Group A, AF was terminated during EEPVI in 5, ASA at left atrial septum in 2, then finally converted to SR either directly or via CTI-dependent atrial flutter in all 7 patients. In contrast with Group B, AF termination during CA was achieved in 11 included 8 patients requiring ASA. During follow up of 3.1±1.3 months, AF-free rate was 83% in Group A, and 76% in Group B (p=0.54). Conclusion: CA mainly by thoracic vein isolation brought favorable outcome in PerAF patients with successful PC.