Interconnections between Left Atrial Ganglionic Plexi: Insights from Minimally Invasive Maze Procedures and Their Outcomes

BACKGROUND: Ganglionic plexi (GPs) have been implicated as triggers of atrial fibrillation (AF) and are known to have functional interconnections. Understanding these connections could result in a more effective ablation. The objective of this study is to assess relationships between right- and left-sided GPs in patients undergoing mini-maze (MM) surgery. We also analyzed the impact of these findings on AF recurrence. METHODS: The GPs were accessed thoracoscopically right side first (group 1) or left side first (group 2). GPs were identified by high-frequency stimulation at 20 predetermined sites and ablation of GPs was performed using a selective or an empiric anatomic approach. Ganglionic plexus (GP) activity was then assessed on the contralateral side and ablated. RESULTS: Sixty-seven patients underwent MM (45 patients in group 1 and 22 in group 2). Fewer patients with active left GPs (LGP) were noted in group 1 (13, 29%) as compared to group 2 (18, 82%). The number of active LGP was also lower (0.6 ± 1.2) in group 1 compared to group 2 (4.7 ± 2.7); P < 0.0001. No significant differences were noted in the frequency of identifiable right GPs (RGP) between groups 1 and 2 (P > 0.05). There were no differences in atrial tachyarrhythmia (AT)/AF recurrence rates between groups 1 and 2 (P = 0.21). However, group 1 patients who underwent selective GP ablation alone had higher recurrence rates (P = 0.016). CONCLUSION: Mapping and ablation of RGPs first decreased identifiable LGP activity. With selective GP ablation, patients who underwent RGP ablation first had higher AT/AF recurrence.