Recovery of mitral isthmus conduction leads to the development of macro-reentrant tachycardia after left atrial linear ablation for atrial fibrillation.

Background: Left atrial linear ablation for atrial fibrillation (AF) may be proarrhythmic, leading to left atrial macro-reentrant tachycardia (LAT). Whether due to failure to achieve block initially or to recovery of conduction after ablation is unknown. This study was designed to evaluate the frequency of recovery of mitral isthmus (MI) conduction compared with cavo-tricuspid isthmus (CTI) conduction, and the relationship between recovery of MI conduction and postablation LAT.