Study subjects
The present study was designed as a prospective cross-sectional study and performed in accordance with the tenets of the Declaration of Helsinki. The study protocol was approved by the Institutional Review Board of the Shizuoka Medical Center (approval number: 2019-R32). Written informed consent was obtained from all participants before participation. We recruited 41 patients with highly symptomatic paroxysmal or persistent AF refractory to medical management for circumferential PV isolation between October 2019 and March 2020. The exclusion criteria included previous PV isolation, age <18 years, and inability to provide informed consent. Patients who had a history of open-heart surgery were excluded because it could affect ECs. Moreover, patients with an implanted pacemaker were excluded due to difficulties in performing computed tomography image analysis resulting from artifact from the pacemaker leads.
All antiarrhythmic drugs except for amiodarone were discontinued for at least 5 half-lives before the procedure. Amiodarone was discontinued 4 weeks in advance.