Patients
Written informed consent was obtained from all patients prior to the ablation procedure, and this study was approved by the local ethics committee (Japan Red Cross Yokohama City Bay Hospital 2019-8). A total of 54 consecutive patients with non-paroxysmal AF who were advised to undergo CBA for PVI and LA roof lines were prospectively enrolled between March and December 2019. Patients who underwent additional ablation aiming at the LA posterior wall (LAPW), besides PVI including touch-up ablation with a radiofrequency (RF) catheter or LA roof line ablation, were excluded. All patients underwent three-dimensional computed tomography (3DCT) and transthoracic echocardiography (TTE) before ablation. Anatomical factors including pulmonary vein (PV) diameter and those related to the esophagus were analyzed via 3DCT using a computer workstation (Ziostation, Ziosoft Inc., Tokyo, Japan). The relationship between the LA roof and esophagus is depicted inFigure 1 . Paroxysmal AF was defined as AF terminating within 7 days, based on a prior definition.9 Baseline demographic characteristics, comorbidities, and medications were recorded.