20℃低温稀释血停搏液心肌保护效果的实验研究

Myocardial protective effect of 20℃ hypothermia blood cardioplegia

目的 研究 2 0℃低温稀释血停搏液 (2 0℃HBC)灌注结合体循环自然降温在心脏直视手术中的心肌保护效果。方法 将 14条 15～ 2 0kg成年杂种犬随机分成对照组和实验组 (n =7) ,雌雄不拘。实验组采用间断 2 0℃HBC灌注 ;体温自然降至 32～ 35℃。对照组采用体循环主动降温 ;间断 8～ 10℃稀释血停搏液 (CBC)灌注。于主动脉阻断前、后抽取右房血测乳酸脱氢酶 (LDH)、肌酸激酶同工酶 (CK MB)、肌钙蛋白I(cTn I) ,取左心室心内膜下心肌观察超微结构变化 ,于主动脉阻断前、后监测心功能。结果 两组停搏液灌注后LDH、CK MB、cTn I均升高 ,实验组变化幅度小 (P <0 0 5 ) ;实验组与对照组相比 ,灌注液对心功能影响较小 ,心肌超微结构损伤性变化不明显。结论 在体外循环过程中 ,与CBC相比 ,在心肌酶、cTn I、心肌超微结构方面2 0℃HBC灌注对心肌有较好的保护作用。

Objectives To evaluate the effects of 20℃ hypothermia blood cardioplegia during cardiopulmonary bypass. Methods 14 mongrel dogs(15～20 kg) were randomly divided into two groups:experimental group and contral group, cardiopulmonary bypass was conventionally instituted, 20℃ Hypothermia Blood Cardioplegia was used in experimental group,cardial function was measured before and after cardiopulmonary bypass.Blood samples from right atrium were taken for examination of lactate dehydrogenase (LDH)creatine kinase(CK-MB) and TroponinI(cTn-I) specimens of left ventricular subendocardial myocardium were biopsied to observe changes of ultrastructure. Results LDH?CK-MB?cTn-I increased after reperfusion in both groups,but the extent of changes in experimental group was tiny (statistical difference).Compared with contral group an effect of 20℃HBC on cardial function was little,the ultrastructure of cardiac muscle had no obvious change. Conclusions 20℃ HBC have protective effect on myocardial reperfusion during cardiopulmonary bypass.