Isolated AVN-FP ablation completely eliminated vagus trunk stimulation-induced sinus rate slowing, AF inducibility, and ERP shortening in dogs compared to baseline (all P < 0.05).
p-value: p=<0.05
BACKGROUND: The epicardial fat pad (FP) integrates the autonomic innervation between the extrinsic and intrinsic cardiac autonomic nervous system and affects atrial electrophysiology and pathophysiology. METHODS: Eighteen dogs were divided into two groups: sequential ablation of sinoatrial node FP (SAN-FP) and atrioventricular node FP (AVN-FP). Sinus rate (SR), atrial fibrillation (AF) inducibility, and effective refractory period (ERP) changes during electrical stimulation of the vagus trunk were detected before and after ablation. RESULTS: In the SAN-FP group, the SR slowing, increasing AF inducibility, and ERP shortening that induced by vagus trunk stimulation were significantly attenuated by isolated SAN-FP ablation, compared with the same group prior to ablation (all P 0.05). In the AVN-FP group, SR slowing, increasing AF inducibility, and ERP shortening that induced by vagus trunk stimulation were completely eliminated by isolated AVN-FP ablation, compared with the same group prior to ablation (all P 0.05). CONCLUSIONS: A neural pathway from the cervical vagus trunk to the sinus node and atrium runs through the SAN-FP, but eventually converges at the AVN-FP and also suggested that the AVN-FP serves as an "integration center" for the SAN-FP to modulate sinus node function. The AVN-FP may play a more critical role in the initiation and maintenance of AF.
Zhou et al. (Tue,) conducted a other in Atrial fibrillation and sinus node function (n=18). Sequential ablation of SAN-FP and AVN-FP vs. Prior to ablation (baseline) was evaluated on Sinus rate, AF inducibility, and ERP changes during electrical stimulation of the vagus trunk (p=<0.05). Isolated AVN-FP ablation completely eliminated vagus trunk stimulation-induced sinus rate slowing, AF inducibility, and ERP shortening in dogs compared to baseline (all P < 0.05).