Prevalence of ERAT after surgical AF ablation
There are limited data available on the occurrence of ERAT after surgical AF ablation. Our study is the first to validate the blanking period after surgical AF ablation. Few studies reported the prevalence of ERAT after surgical AF ablation. 6,10-13 Benussi et al.13 studied the prevalence of ERAT in 132 patients undergoing surgical AF ablation. ERAT occurred in 49.2% of patients, and the one-year freedom for AF recurrence was significantly lower in patients with in-hospital postoperative arrhythmias. However, previous studies were insufficient to estimate the prevalence of ERAT after surgical AF ablation because the total number of patients was relatively small and data collection was limited to within the postoperative stay. For these reasons, unlike catheter ablation, ERAT within a 3-month blanking period after surgical AF ablation has not been established. Postoperative AF is the most common atrial arrhythmia after cardiac surgery and is usually a transient condition that resolves spontaneously.14 Cardiac surgery itself provides extensive arrhythmogenic substrates with pre-existing cardiac fibrosis for triggering and perpetuating AF during the perioperative period.15-17 At the same time, concomitant surgical AF ablation with cardiac surgery also causes the modification of arrhythmogenic substrates, such as triggered activity of the pulmonary veins or re-entry-promoting structural and electrical remodeling. The positive and negative effects of ERAT occurred in the immediate post-operative phase. Unlike several studies on the blanking period of catheter AF ablation,18-20, our study included mostly patients undergoing cardiac surgery, such as valve repair or replacement and coronary artery bypass grafting. Therefore, there may be a drawback in simply accepting the blanking periods after surgical AF ablation based on the blanking periods after catheter ablation. Nevertheless, approximately half of the patients (49%) experienced ERAT within the first three months following surgical AF ablation, which is consistent with prevalence rates between 15.9% and 65% of patients with catheter AF ablation in previous studies.16-18 Previous studies showed that ERAT occurred in the majority of patients within the first month after catheter AF ablation, and it gradually decreased; almost all ERAT occurred within the first two months. 18,20 Our data founded that ERAT occurred in more than half of the total number of patients (65 patients) within the first month and slightly rebounded up to 37.8% in the third month after the index procedure.