心肌缺血和再灌注早期心内、外膜下心室肌细胞动作电位时程和传导变化

Changes in action potential and the conduction time of ventricular cells in subendocardium and subepicardium during ischemia and early reperfusion

目的 :探索心肌缺血时心内膜下心肌和心外膜下心肌电活动变化特征。方法 :应用修改的Ferrier豚鼠离体右心室壁“缺血”及“再灌注”研究法。结果 :心肌缺血时和再灌注早期心内膜下和心外膜下心室肌细胞跨膜电活动均明显异常 ,且以内膜下更明显。结论 :心肌缺血和再灌注早期损伤造成心内、外膜下心室肌电活动变化程度不同 ,这种不同可能是心内膜下心肌缺血易损性的电生理学基础。

AIM: To investigate the electrophysiological characteristics of ventricular myocyte both in subendocardium and in subepicardium during ischemia. METHODS: Using modified Ferrier's method of ischemic and reperfusion injury in isolated guinea pig right ventricular wall. RESULTS: The transmembranal electric activities in subendocardium and in subepicardium were all significantly abnormal, and it was more significant in subendocardium. CONCLUSION: The alteration degree of ventricular myocyte in subendocardium and in subepicardium during ischemia and early reperfusion was different, and this might be the electrophysiological basis of the vulnerability of the subendocardium.