Study population
382 consecutive AF patients undergoing index radiofrequency ablation procedure from January 2019 to July 2022 were retrospectively enrolled. Exclusion criteria included: (1) Unsuccessful PV isolation; (2) Unable to maintain sinus rhythm during mapping of insertion sites; (3) Both AEPVR and endocardial gap present in a single case. All patients provided written informed consent. The study protocol was approved by the institutional review board of Huashan Hospital Fudan University (KY2023-485).