肢体缺血预处理对心脏瓣膜置换术心肌保护作用的研究

Clinical study of limb ischemic preconditioning on myocardial ischemia-reperfusion injury during open heart surgery

目的:探讨肢体缺血预处理(IPC)在心脏瓣膜置换术中对心肌缺血再灌注损伤的保护作用。方法:30例心脏瓣膜置换术患者随机分为IPC组和对照组。IPC组在主动脉阻断前10min内,用气压止血带绑于右上臂上部,给于300mmHg的压力,阻断右上肢血流,持续3min,开放2min后,再重复上述过程一次;对照组不给缺血预处理。记录两组临床指标及心肌电生理指标;分别于主动脉阻断前,主动脉开放即刻、开放后3h、6h、12h、24h抽取桡动脉血,检测心肌酶肌酸酶同工酶(CK-MB)、肌钙蛋白I(cTnI)的水平;观察心肌超微结构变化。结果:两组开放后辅助循环时间IPC组明显低于对照组(P<0.05);对照组术后室性心律失常发生率、需重复除颤率明显高于IPC组(P均<0.01);主动脉开放后12h心肌酶CK-MB及cTnI对照组明显高于IPC组,分别为[(141.9±21.2)U/L∶(98.9±17.3)U/L,(5.157±1.207)ng/ml∶(2.113±0.984)ng/ml,P<0.05,<0.01]。IPC组心肌超微结构保存较好,损伤较对照组轻(P<0.01)。结论:肢体IPC可减少心肌酶漏出,降低术后室性心律失常发生率,减轻心肌超微结构损伤,对心肌缺血再灌注损伤有保护作用。

Objective：To evaluate the myocardial protective effect of limb ischemic preconditioning on myocardium ischemia-reperfusion injury during heart valve replacement surgery.Methods：Thirty patients required heart valve replacement were divided randomly into two groups：IPC group（n=15）and control group（n=15）.A airpressure tourniquet wrapped around the right upper extremity of the patient,was inflate and deflate twice to perform 3 min of its limb ischemia and 2 min of its limb reperfusion in the IPC group at the 10 minutes before aorta clamping.CK-MB（creatine kinase-MB）and cTnI（cardiactroponin-I）were measured in two groups respectively before cardiopulmonary bypass（CPB）and immediately,3h,6h,12h,24h after CPB,from the patient＇ radial arterial blood samples.Myocardial ultrastucture changes in two groups were assessed.Results：The supplementary circulation time in IPC group was much shorter than that of control group（P〈0.05）.The frequence of defibrillation and the incidence of ventricular arrhythmia of IPC group were less than those of control group（P〈0.01 all）.The Serum concentration of CK-MB and cTnI levels in control group and IPC group respectively were（141.9±21.2）vs.（98.9±17.3）U/L;（5.157±1.207）vs.（2.113±0.984）ng/ml（P〈0.05,〈0.01）after aorta off-clamping 12 h.The myocardial ultrastructure damage in IPC group was significantly less than that in the control group（P〈0.01）.Conclusion：Limb IPC can significantly reduce the postoperative ventricular arrhythmias,the leakage of myocardial enzyme CK-MB and cTnI and the injury of the myocardial ultrastructure,that possess protective effect on myocardial ischemia-reperfusion injury.