3.1. Patients
This observational study enrolled consecutive patients who underwent PVI alone as an initial AF ablation procedure at Kansai Rosai Hospital between March 2017 to November 2018. Patients in whom a voltage map was not obtained due to unstable cardiac rhythm were excluded. Patients with left atrial linear or area ablations were also excluded. This study complied with the Declaration of Helsinki. Written informed consent for the ablation and participation in the study was obtained from all patients, and the protocol was approved by our institutional review board.