心内膜单相动作电位与缺血性心律失常关系的实验研究  

Correlation Between the Parameter Changes of Monophasic Action Potentials and Tachyarrhythmias due to Coronary Occlusion in Dogs

作　　者：张薇[1] 曹琼[1] 王子法[1] 隋树建[1] 尹红[1] 刘旭[1] 丰建伟 

机构地区：[1]山东医科大学附属医院心内科,济南250012

出　　处：《起搏与心脏》1993年第2期98-101,共4页

摘　　要：应用心内膜接触电极导管,记录犬缺血-再灌注时在体心脏左室单相动作电位(MAP),观察急性心肌缺血对 MAP 的影响及其与心律失常、心电图改变的关系。15只犬,共行缺血(20min)-再灌注实验24次.缺血时 MAP 振幅(MAPA)由对照的28±4mV 降至17±4mV(P<0.001),MAP 平台相由对照的134±15ms 缩短至112±14ms(P<0.001),于再灌注1min 内恢复至对照水平.缺血性心律失常的发生有2个高峰期,分别发生于冠状动脉结扎1～7min 及14～19min.其发生前均有 MAPA、MAP 平台相或 MAP3相的交替变化,伴有缺血区左心腔电图 ST—T 电交替.结果表明:MAPA 降低、MAP 平台相缩短是局部心肌缺血的特异性电生理学改变;MAP 和 ST—T 电交替现象反应了心电活动紊乱及复极非均质性,是发生严重心律失常的预兆。Monophasic action potentials(MAP)were recorded by endocardial contact elec- trode during coronary occlusion and reperfusion to investigate correlation between the parameter changes of MAP,intracavitary electrocardiogram and ischemic taehyarrhythmias.In 15 dogs,24 tri- als of 20 minutes of occlusion of left descending artery were followed by reperfusion.During is- chemia,MAP amplitude was reduced from 28±4mV to 17±4mV(P<0.001),plateau duration reduced from 134±15ms to 112±14ms(P<0.001).After release of the occlusion,MAP amplitude and plateau duration increased to control level.Two periods of ventricular arrhythmias which oc- curred 1～7 minuts and 14～19 minuts respectively after coronary ligation were clearly seen.Alter- nation of beat to beat in the amplitude,plateau duration and phase 3 of MAP were associated with alternations of ST-T of intracavitary electrocardiogram and were always preceding the develop- ment of ventrieular tachyarrhythmias during occlusion.The results suggested that MAP recording could be used as a reliable electrophysiologic index for evaluating ischemia.Alternation of MAP amplitude,plateau duration,phase 3 and ST-T minght be a sign of predysrhythmias and reflect an unstable electrical state of the myocardium and heterogeneity of refractoriness.

关 键 词：单相动作电位 心肌缺血 心律失常 

分 类 号：R541.7[医药卫生—心血管疾病]