动脉压力感受性反射对兔室性心律失常心外膜单相动作电位的影响

摘要

目的 探讨动脉压力感受性反射(ABR)对兔缺血性室性心律失常时心外膜单相动作电位(MAP)的影响.方法 采用闭胸记录兔心外膜MAP和心电图的技术,观察心肌缺血背景下致心律失常前后各组MAP参数的变化.结果 在去窦弓神经组(n=10),与缺血前相比,心率(HR)减慢,心外膜振幅(MAPA)降低,0相最大上升速率(Vmax)减慢,MAPD50和MAPD90缩短(P＜0.05),与单纯缺血组(n=10)相比,HR加快,MAPA增加(P＜0.05),而Vmax、MAPD50和MAPD90无明显变化；在美托洛尔组(n=9),用美托洛尔预处理后,与缺血前相比,HR减慢、心外膜MAPA降低、Vmax减慢(P＜0.05),而MAPD50和MAPD90无明显变化；与单纯缺血组相比,心外膜MAPA增加、MAPD50和MAPD90延长(P＜0.05),而HR和Vmax无明显变化.结论 ABR可影响缺血性室性心律失常心外膜MAP改变程度,可能参与缺血性室性心律失常的发生发展过程.%Objective To investigate the effects of artenaf baroretlex (ABK) on epicardial monophasic action potential (MAP) in ventricular arrhythmia in rabbits. Methods The changes of the MAP parameters following myocardial ischemia were observed with the technique for simultaneously recording the epicardial MAP and surface electrocardiogram in rabbits in situ. Results In the sinoaortic denervation ( SAD) group (n = 10), the heart rate ( HR) , amplitude ( MAPA) and maximum of depolarization velocity of the zero phase (Vmax) of MAP decreased, MAP duration including MAPD50 and MAPD90 shortened (P<0.05) after ischemia, compared with those at the baseline; whereas compared with the ischemic group (n = 10) , HR and MAPA increased (P<0. 05) , Vmax, MAPD50 and MAPD90 didn't change. In the metoprolol group, after ischemia, compared with the baseline, HR, MAPA and Vmax decreased ( P < 0. 05 ) , MAPD50 and MAPDW didn't change; whereas compared with the ischemic group, MAPA increased, MAPD90 and MAPD90, was prolonged ( P < 0. 05 ) , HR and Vmax didn't change. Conclusion ABR could affect the changes of MAP in ventricular arrhythmia induced by ischemia, and then participated in the ventricular arrhythmogenesis.