自主神经干预对心房恢复性质的影响

Objective This study aimed to investigate the effects of autonomic interventions on the restitution properties on the atria. Methods In 10 open-chest dogs,multiple electrode catheters were sutured at multiple pulmonary vein(PV) and atrial sites. The monophasic action potential was recorded by an AgAgCl catheter. The restitution curve at each site was constructed before and after vagal stimulation or ganglionated plexi(GP) ablation. The atrial fibrillation(AF) inducibility and duration induced by burst pacing were measured at each site before and after ipsolateral vagal stimulation or GP ablation. Results Before GP ablation, vagal stimulation markedly shortened the action potential duration (APD), decreased the slope of the restitution curves and the APD alternans cycle length, while increased the AF inducibility and duration once induced at each site( P ＜ 0. 05 ). These effects were eliminated by GP ablation. Compared to baseline,GP ablation significantly increased the APD, steepened the restitution curves and facilitated the APD alternans while decreased the AF inducibility and duration ( P ＜ 0. 05 ). VNS significantly increased ( 0. 5 ± 0. 2 vs. 0. 3 ±0. 1 ,P ＜ 0. 05 ) and GP ablation decreased (0. 2 ± 0. 1 vs. 0. 3 ± 0. 1, P ＜ 0. 05 ) the spatial dispersion of the slopes of APD restitution curves, respectively. Conclusions The maximal slope of APD restitution curve alone does not fully account for the changes of AF inducibility and duration induced by autonomic interventions; instead, the spatial dispersion of the APD restitution curves of Smax may be an important determinant for susceptibility of AF.

Effects of autonomic interventions on atrial restitution properties