Introduction. Catheter-based or surgical procedures in patients with long-standing persistent atrial fibrillation (LSPAF) remain a challenge. As a result, different approaches including hybrid (surgical and endocardial) ablation have been developed. Bachmann’s bundle (BB) is a mainly epicardial structure capable of sustaining arrhythmic reentry that could be involved in the development and perpetuation of atrial fibrillation. We investigated the efficacy and safety of an adjunctive BB ablation in LSPAF patients undergoing hybrid ablation. Methods. In a two arm non randomized study, consecutive LSPAF patients undergoing epicardial isolation of pulmonary veins with left atrial posterior wall (box-lesion) with (n=30, BB-group) and without additional BB ablation (n=30, CONV-group) were enrolled in the study. All patients underwent an endocardial procedure within 6 weeks post-surgery to assess for potential lesion gaps and additional atrial substrate modification. The primary endpoint was freedom from AF through 12 months of follow-up. Results. The two-staged hybrid ablation was successfully completed in all patients. One-year freedom from atrial arrhythmias recurrence rates was 96.6% in the BB group vs 76.6% in the CONV group (p=0.025). At procedure completion, 30 (100%) and 17 (56%) patients had a spontaneous cardioversion in BB and CONV group respectively (p < 0.001). No significant differences in quality of life or complication rates were observed. Conclusions. This initial experience shows, for the first time, that adjunctive BB ablation in the setting of hybrid ablation for LSPAF is a feasible and effective approach in increasing maintenance of sinus rhythm without increasing complication rates.

Percutaneous atrial septal defect (ASD) closure is the mainstay treatment for ostium secundum ASD and patent foramen ovale1. Patients with ASD may develop atrial fibrillation (AF), mostly due to structural atrial remodeling creating the substrate for macroreentry2,3. Timing of ASD closure is crucial to prevent further development of electrophysiological heterogeneity, thereby reducing morbidity associated with AF, even though patients with ASD closure devices remain at high risk of developing AF4.The rising number of patients undergoing percutaneous ASD closure poses a new challenge in the treatment of coexistent AF. Furthermore, the reduction of surgical ASD treatment with concurrent cryo- or radiofrequency ablation (modified Maze procedure) is contributing to increase the number of patients who would benefit from catheter ablation after transcatheter ASD closure. Although some studies have shown a high acute success rate of catheter ablation in this population5, this treatment is often denied due the higher perceived risk of performing the transseptal puncture (TSP) after percutaneous repair of the defect.Given the lack of definitive data on this topic, in this issue of the Journal, Garg et al. performed the first meta-analysis evaluating the safety and the efficacy of catheter ablation for AF in this subset of high-risk patients with ASD closure devices.