缺血预适应对体外循环心肌保护作用的临床研究

目的：比较单用冷停博液与缺血预适应（IPC）加冷停搏液联合应用在先天性心脏病心内直视手术中的心肌保护效果。方法：先天性心脏病病人20例，随机分为缺血预适应组（IPC组,n=10)和对照组（n=10),IPC组在阻断升主动脉前实施3分钟缺血－5分钟再灌注的缺血预适应，然后阻断升主动脉，灌注冷（4℃）St Thomas‘停搏液，心脏完全停跳后开始心内手术；对照组则不进行缺血预适应方案。两组均于并行循环前，开放升主动脉心脏复跳后30，60分钟时经Swan-Ganz漂浮导管测定各项血液动力学指标，并观察心肌功能恢复情况；于并行循环前，开放升主动脉时取心肌行超微结构检查及ATP，MDA测定，IPC组还监测缺血预适应期间的心电图及动脉血气变化。结果：（1）CPB后IPC组血液动力学指标恢复快（P＜0．05），心肌收缩有力，血压维持良好，需辅用多巴胺等正性肌力药维持血压的病例明显少于对照组（P＜0．05）；（2）升主动脉开放时IPC组心肌超微结构；ATP等的保护明显优于对照组（P＜0．05），MDA的生成明显低于对照组（P＜0．05）；（3）IPC组阻断升主动脉期间ST段降低（阻断30秒时发生），开放升主动脉后ST段在15秒内完全恢复，此期间均未发现明显心律失常；IPC前后血气结果无明显变化。结论：缺血预适应加冷停博液联合应用具有良好的心肌保护作用。

Clinical study of ischemic preconditioning on myocardial protection during cardiopulmonary bypass

Objective To evaluate the protective effects of ischemic preconditioning(IPC) with cold cardioplagia on myocardial reperfusion injury.Methods Twenty congenital heart disease patients were devided into two groups randomly.Control group (n=10) received intermittent cold crystalloid cardioplegia perfusion.IPC group (n=10) received IPC by clamping aorta 3min followed by declamping 5min before cold cardioplegia perfusion.Hemodynamic parameters,myocardial ATP content,myocardial MDA content and ultrastructaral changes were detected at different time points.Results (1)Hemodynamic parameters in IPC group were maintained better than those in control group,and recovered to normal value 30min after reperfusion.(2)The percentage of normal mitochondria and glycogen,the levels of ATP and energy charge(EC) were significantly higher in IPC group than those in control group during aorta declamping(P<0.05).In control group,MDA was significantly elevated during ischemic(P<0.05).While in IPC group,there was no obvious changes.Conclusion Ischemic preconditioning plus cold cardioplegia perfusion provide a better myocardial protection during CPB.