常温体外循环下采用缺血预调行心肌保护的研究

Experimental Study on Myocardial Protection of Ischemic Preconditioning during Normothermic Extracorporeal Circulation

为了探讨常温体外循环下采用缺血预调行心肌保护的研究,通过建立犬的常温体外循环全心缺血预调模型,旨在探讨心内直视手术缺血预调保护心肌的可能性。预调组采用升主动脉阻断5分钟,放开10分钟,反复三次的方式预调心脏;对照纽简单并行循环45分钟,而后两组均接受30分钟缺血和60分钟再灌注。结果显示,预调组室颤发生率低(16.7 VS 83.3％P=0.04),无再灌注心律失常(0 VS66.7％P=0.03),心肌ATP消耗减慢(4.69+1.050 VS 2.35±0.86μmol/g wet wt P<0.01),乳酸积累减少(4.49±0.86 VS 9.80+5.53mg/g wet wtP<0.05),心肌细胞超微结构损伤轻。结论:常温体外循环下应用缺血预调保护犬的心肌是可行而有效的。

A global ischemic preconditioning model was established during normothermic extracorporeal circulation to investigate the myocardial protectin of ischemic preconditioning in open heart surgery. The experimental dogs were randomly divided into two groups. 6 dogs in preconditioned group were preconditioned by 5-min period of cross-clamping interposed with 10 min of reperfusion, then followed by an ischemic insult of 30 min of aortic clamping and 60 min of reperfusion. 6 dogs in control group only received the ischemic insult of 30 min of aortic clamping and 60 min of reperfuion. The results demonstrated ischemic preconditioning reduced the incidence of ventricular fibrillation induced by aortic clamping (16.7% vs 83. 3 % , P-0. 04 )and the incidence of arrhythmias during reperfusion (0 vs 66.7% , P = 0. 03), and also delayed myocardial ATP depletion (4.69±1.50 vs 2.35±0.86nmol/g wet weight, P<0. 01) and accumulation of myocardial lactate (4. 49±0.86 vs 9. 80±5. 53 mg/ g wet weight, P<0. 05). It was concluded that it waspossible and useful to precondition dog heart during normothermic extracorporeal circulation.