Study population
The study population was retrospectively analyzed and originated from a database of patients who underwent catheter ablation for AF at Nagoya University Hospital, Japan. All patients who were scheduled to undergo catheter ablation for AF which involved the LA at our center from January 2007 to July 2021 were included in the study. Patients with a history of MAZE procedure and thrombi formation prior to the initial session and with major adverse events during the first session were also included in the study. The exclusion criteria were as follows: detection of thrombi at the first session; and undergoing ablation for the right atrium only. We reviewed the medical records, examination data, and procedures in the databases of all eligible patients. The indications for catheter ablation complied with the most recent guidelines.3 Antiarrhythmic agents were discontinued at least five half-lives before ablation. Informed consent for the procedure was obtained from all patients. The study protocol was approved by the institutional ethics committee. The study was performed in accordance with the principles of the Declaration of Helsinki.