【摘要】 目的:研究缺血-再灌注性心律失常的电生理机制。方法:20只杂种犬随机分成对照组及实验组各10只。实验组有分成单纯用药组及用药起搏组。开胸结扎冠脉前降支,记录缺血区单相动作电位及缺血区、缺血边缘区、正常区心内膜下双极电图。结果:(1)77.8％(7/9)的IA与异常双极电图有关,22.2％(2/9)的IA与EADs诱发的触发活动有关。(2)58.3％(7/12)的RA与EADs诱发的触发活动有关,25%(3/12)的RA与异常双极电图有关,其余17％的RA发生机制不清。(3)硫氮唑酮能显著降低IA及RA的发生率。结论:MAP技术及双极电图是研究IA及RA的可靠方法,硫氮唑酮能显著降低IA及RA的发生率。更多还原

【Abstract】 Objective: To investigate the electrophysiologic mechanisms of ischemia induced and reperfusion arrhythmias and the effective mechanisms of diltiazem. Methods: We ligated the left anterior descending coronary artery (LAD) of mongrel dogs to study the mechanisms of ischemia - induced and reperfusion arrhythmias and effective mechanisms of diltiazem. The 20 mongrel dogs weie divided into study group and control group randomly. The endocardial MAP of ischemic zone was recorded by a contact electrode catheter, and meanwhile, the bipolar electrograms of ischemic zone were recorded by self - made needle electrodes. At the same time, lead Ⅱelectrocardiogram and left ventricular pressure were recorded. Results: (1) 77.8% (7/9) of ischemic arrhvthmias were relat-ed to abnormal bipolar electrograms. Delayed activation fractionated electrical activity and continuous electrical activity had been ob-served in ischemic myocardium in the sinus rhythm. 22.2% (2/9) of ischemic arrhvthmias were associated with triggered activities induced by early after depolarizations(EADs) . (2) 58.3% (7/12) of reperfusion arrhvthmias were related to the triggered activities induced by EADs, and 25% (3/ 12) of reperfusion arrhythmias had something to do with abnormal bipolar electrograms, which were quite similar with the alterations during IA. The mechanism of the 19% of RA is unclear. (3) The occurrence rate of IA and RA may be significanth/ decreased by the use of diltiazem. Conclusion: (1) The MAP technique and bipolar elecrrogram is a reliable method to study ischemia - induced and reperfusion arrhythmias. (2) Diltiazem can prevent and cure the ischemia- induced and reperfusion arrhvthmias effectively.更多还原