Catheter ablation of incisional atrial tachycardia using a novel mapping system: LocaLisa

Abstract

Incisional atrial tachycardia occurs due to reentry around surgical scars. Pharmacological therapy is often ineffective. This study assessed the efficacy of a novel mapping system (LocaLisa) in facilitating catheter oblation of incisional atrial tachycardia circuits. Right consecutive patients (four men, four women) with incisional atrial tachycardia (median age 23.5 years, range 9-44) following previous repair of congenital heart defects underwent trunscutheter mapping and oblation of the arrhythmogenic substrute using u mapping system (LocaLisa) that allows localization of endocardial electrodes in a three-dimensional space. Critical isthmuses for the tachycardia circuits were identified by demonstrating concealed entrainment using standard pacing and mapping techniques. Scars and natural anatomic barriers were marked on the LocaLisa image. Lines of block were created by radiofrequency current application between scars and natural anatomic barriers, or between two scars, to close isthmuses demonstrated to be critical for the reentrant circuit. All lines of block were verified in both directions. All reentrant circuits around incisions were successfully ablated. Seven additional tachycardia mechanisms were identified in four patients (common atrial flutter [n = 4], atrioventricular nodal [AVN] reentry [n = 2], ectopic atrial tachycardia [n = 1]) and were also ablated in a single session. The mean fluoroscopy time was 28.4 ± 13.8 minutes. All patients ore arrhythmia-free at a median follow-up of 20 (6-22) months. The LocaLisa mapping system is effective for identification of scars and oblation targets, for confirming lines of block, and facilitating ablation of complex reentrant circuits.