Mapping and Ablation of Left Atrial Flutters

Abstract

Background —Typical right atrial isthmus–dependent flutters have been described in detail, but very little is known about left atrial (LA) flutters. Methods and Results —We performed conventional and 3D mapping of the LA for 22 patients with atypical flutters. Complete maps in 17 patients demonstrated macroreentrant circuits (n=15) with 1 to 3 loops rotating around the mitral annulus, the pulmonary veins, and a zone of block or a silent area. In 2 patients, a small reentry circuit with a zone of markedly slow conduction was identified. Linear ablation performed across the most accessible part of the circuit cured 16 patients (73%) with a follow-up of 15±7 months. Conclusions —LA reentrant tachycardias are related to individually varying circuits and are amenable to mapping guided radiofrequency ablation.