心外膜脂肪垫网络迷走神经干对窦房结和房室结功能的影响

Effects of network interaction between epicardial fat pad and vagal nerve trunk on sinoatrial nodal and atrioventricular nodal functions

目的探讨心外膜窦房结脂肪垫（SAN-FP）和房室结脂肪垫（AVN—FP）网络迷走神经干调控心脏活动的主控区。方法杂种犬18只，分为A组和B组，以不同电压分别刺激左右迷走神经干、SAN．FP和AVN—FP，测定窦性心率（SR）和AH间期，A组先消融SAN—FP，在刺激迷走神经干的情况下测定SR和AH间期，再联合消融SAN—FP和AVN—FP，B组则先消融AVN—FP，再联合消融AVN-FP和SAN-FP。结果①右侧迷走神经干刺激产生的迷走效应强于左侧（SR减慢75％对41％），SAN—FP刺激引起SR减慢的最大幅度为13％；②优先消融SAN—FP后刺激迷走引起SR减慢的效应显著减弱，AH间期显著延长，联合消融后刺激迷走对SR的影响与消融前差异无统计学意义，但AH间期较消融前和单独消融时均显著延长；③优先消融AVN—FP刺激迷走引起SR减慢效应较消融前差异无统计学意义，AH间期较消融前明显延长，联合消融后刺激迷走对sR和AH间期的影响较单独消融时差异无统计学意义。结论迷走神经干刺激的迷走效应右侧大于左侧，右侧迷走神经干主要通过AVN—FP调控窦房结功能。心外膜脂肪垫是迷走神经干调控窦房结和房室结功能的重要环节，AVN—FP是主控区，SAN-FP为辅助区。

Objective To explore effects of network interaction between epicardial fat pad and Vagal Nerve Trunk on sinoatrial nodal （ SAN ） and atrioventricular nodal （AVN） functions. Methods Eighteen dogs were divided into two groups. High frequency electrical stimulate （ 1000 bpm,2 ms ,0. 5 -4.0 V） vagal nerve trunk,sinus-atrial node fad pad（SAN-FP） and atria ventricular node fad pad（AVN-FP）. In SAN-FP pre-abla- tion group, SAN-FP ablation was performed at first, then AVN-FP ablation was combined, sinus rate （SR） and AH internal were detected during vagal stimulation before and after AVN-FP ablation. The AVN-FP pre-ablation group was performed in the same way. Results （1）The vagal effect induced by right vagal nerve trunk electrical stimulation was larger than left vagal nerve electrical stimulation （SR decreased 75% vs. 41% ）. The reduction of SR induced by SAN-FP stimulation was no more than 13%. （2）In SAN-FP pre-ablation group, the reduction of SR was significantly decreased and AH internal was significantly prolonged compared with baseline, and induced by vagal stimulus after SAN-FP ablation. SAN-FP plus AVN-FP ablation did not induce significant change in SR compared with baseline, however,there was statistically significant prolongation in AH internal, compared with baseline and SAN-FP single ablation. （3）In AVN-FP pre-ablation group, vagal stimulus after SAN-FP ablation didn＇t induced significant change in SR, but A-H internal was significantly prolonged. AVN-FP plus SAN-FP ablation did not induce significant change in SR and A-H internal compared with AVN-FP single ablation. Conclusions We concluded that vagal effect induced by right vagal nerve trunk electrical stimulation was larger than left vagal nerve stimulation. Right vagal nerve regulated SAN function mainly by AVN-FP. The present study suggested that epicardial fat pad was the important pathway of vagal nerve trunk in regulating SAN and AVN function, and AVN-FP was the main control region and SAN-FP was the associated pathway.