Study population
Patient data in this study were obtained from the Chinese Atrial Fibrillation Registry (CARF), which is a prospective, multicenter, ongoing registry study.7 In CARF, consecutive patients referring to Beijing Anzhen Hospital for catheter ablation of AF were retrospectively enrolled in this study if meeting all the inclusion criteria: (1) age≄18 years old; (2) AF (confirmed by 12-lead ECG or 24-hour Holter monitoring); (3) CLBBB. Exclusion criteria include: (1) valvular AF; (2) hypertrophic cardiomyopathy; (3) a history of catheter or surgery ablation of AF; (4) other wide QRS morphologies (right bundle branch block, ventricular pacing, unclassified intraventricular conduction disturbances). A total of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were screened. Forty-two cases of AF combined with CLBBB were enrolled as CLBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without CLBBB were enrolled in the study as Non-CLBBB group.
CLBBB was defined according to the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society recommendations: native QRS duration >120 ms; broad R waves in leads I, aVL, V5, or V6; absent q waves in leads I, V5, and V6; R peak time > 60 ms in leads V5 and V6 but normal in leads V1, V2, and V3, when small initial r waves can be discerned in the above leads.8 This study was approved by the ethics committee.