Electrophysiological Charactaristics of the Left Atrial Endocardial Surface Close to the Ganglionated Plexi during Atrial Fibrillation

Abstract

Background: Complex Fractionated Atrial Electrogram (CFAE) can contribute to the substrate of atrial fibrillation (AF), and some investigators have proposed that CFAE reflects cardiac autonomic nerve system activity occurring in areas of ganglionated plexi (GP). In this study, we examined the electrophysiological charactaristics of the left atrial sites close to GP. Methods: We analyzed 17 patients refered to our institution for AF ablation. GP was sought by demonstrating parasympathetic response to high-frequency stimulation. If AF sustained, we measured the average AF cycle length at GP sites by using automated calculation systems. Furthermore in 8 cases, we conducted CFAE analysis at the whole area of the left atrium. Results: We could measure the average AF cycle length at 76 GP sites. The values were 30–176 ms (81.5±29.7 ms). At 8 of 76 (10.5%) GP sites, AF cycle length was longer than 120 ms. In 8 cases with entire left atrial CFAE analysis, the shortest AF cycle length in the left atrium was 30–54 ms (43.4±11.4 ms). We could not induce GP responses at the shortest AF cycle length sites except 2 cases. Conclusion: We could induce GP responses at the long AF cycle length sites (over 120 ms). In 6 of 8 cases with CFAE analysis, we could not find GP responses at the shortest AF cycle length sites in the left atrium. In this study, we suggest that CFAE does not always reflect the GP activity.