Predictive Background Characteristics of Primary and Iatrogenic Left Atrial Tachycardias in Patients Undergoing Catheter Ablation of Atrial Fibrillation

Introduction Primary or iatrogenic left atrial tachycardias (LATs) can occur in patients undergoing atrial fibrillation (AF) catheter ablation. We aimed to investigate the background characteristics of the occurrence of LATs during and after AF catheter ablation. Methods and Results We retrospectively studied 5465 consecutive patients who underwent catheter ablation of AF with and without ATs between March 2014 and September 2021. LATs were defined as ATs with those circuits or origins that were partially or completely included in the LA. The LAT and non‐LAT groups included 388 and 5077 patients, respectively. A total of 504 LATs (macroreentry, 80.2%; localized reentry, 10.9%; focal activation, 8.9%) consisted of 31 (6.2%) primary and 473 (93.8%) iatrogenic LATs. A multivariate analysis demonstrated that a female gender, non‐paroxysmal AF, ischemic heart disease (IHD), hypertrophic cardiomyopathy (HCM), cardiac sarcoidosis, larger LA diameter, left ventricular hypertrophy (LVH), and prior LA linear and electrogram‐based ablation were independent positive predictors of LATs (odds ratios [ORs]: 2.00, 1.56, 3.37, 1.85, 16.9, 1.04, 1.90, 2.35 and 3.06; p < 0.05). Further, an older age, non‐paroxysmal AF, IHD, and larger LA diameter were independent positive predictors of primary LATs (ORs: 1.08, 17.1, 4.95, and 1.12; p < 0.05). Conclusions A female gender, non‐paroxysmal AF, larger LA diameter, prior LA linear and electrogram‐based ablation, and the presence of IHD, HCM, cardiac sarcoidosis, and LVH may increase the risk of LATs associated with AF catheter ablation, and an older age, non‐paroxysmal AF, larger LA diameter, and IHD may increase the risk of primary LATs, especially macroreentrant LATs.