Atrial Fibrillation Cycle Length Is a Sole Independent Predictor of a Substrate for Consecutive Arrhythmias in Patients With Persistent Atrial Fibrillation

BACKGROUND—Termination of persistent atrial fibrillation (AF) can be achieved through ablation, with the majority of patients terminating to an atrial tachycardia (AT) and fewer directly to sinus rhythm (SR). We aimed to identify potential predictors for the existence of a substrate for AT on termination to SR. METHODS AND RESULTS—We assessed 95 persistent AF patients (age, 60±10 years) who underwent catheter ablation to the end point of AF termination. Forty patients terminated directly to SR (SRterm) and 55 to ATs (ATterm). Compared with the ATterm group, the SRterm group were younger (56±10 versus 63±9 years, P=0.001), had shorter durations of AF before ablation (9±26 versus 14±20 months, P