不阻升主动脉低温室颤法心内直视手术的临床研究

目的　观察与评价不阻升主动脉低温心室颤动状态下行体外循环心内直视手术的心肌保护效果。方法　选择首次接受体外循环心内直视手术的先天性心脏病病人 4 0例。随机分为低温室颤组 (HF组 )和冷晶体停跳液组 (CC组 ) ,每组 2 0例病人 ,分别行心内直视手术。分别于 6个时点抽取外周静脉血 ,测定并比较两组心肌肌钙蛋白 (cTnI)、磷酸肌酸激酶同工酶(CK MB)、超氧化物歧化酶 (SOD)和脂质过氧化物产物丙二醛 (MDA)在围手术期浓度变化。取心肌电镜标本 ,观察心肌超微结构的变化。结果　HF组和CC组术后 4种酶学指标都升高 ,CC组的cTnI,CK MB ,MDA在大多时点都较HF组升高明显(P <0 .0 5 ) ,其中以cTnI值最为显著 (P <0 .0 1) ,而SOD值低于HF组 (P <0 .0 5 )。心肌超微结构显示HF组心肌损伤较CC组轻。结论　不阻升主动脉低温室颤法与常规阻升主动脉心脏停跳法都可引起心肌损伤 ,但低温室颤法损伤程度明显轻于停跳法 ,可以推荐为一种安全、可行的心肌保护方法

Clinical study of hypothermic ventricular fibrillation for open-heart surgery with cardiopulmonary bypass

Objective To access the effect of usinghypothermic ventricular fibrillation technique for open-heart surgery on myocardial protection. Methods There were 40 patients with congenital heart disease ventricular septal defect who underwent the cardiac surgery procedure first The patients were randomly divided into two groups equally: control group experienced cold crystalloid cardioplegia (CC,n=20) and experimental group received hypothermic ventricular fibrillation with no aortic cross-clamping (HF,n=20). Serum cardiac troponin I (cTnI), creatine kinase MB (CK-MB),superoide dismutase (SOD) and malonyldialdehyde (MDA) were measured . In all the patients,myocardial tissues were taken from right atrium for observing the myocardial ultrastructure changes. Results All serum enzymes increased in both groups HFand CC postoperatively. The serum level of cTnI, CK-MB and MDA was significantly lower in group HF than in group CC (P<0.05), especially the level of cTnI(P<0.01). The level of SOD was higher in group HF than in group CC postoperatively (P<0.05). The myocardial ultrastructure damaged postoperatively ingroup CC and there were no significant chang before and after the process of CPBin group HF. Conclusion Since there are no aortic clamping and perfusioncardioplegia,and no ischemic-reperfusion injury, the hypothermic ventricular fibrillation technique can reduce the myocardial injury. So it is a safe way on myocardial protection in open-heart surgery.