体外循环下低温室颤性停搏心肌损伤程度的评估

Experimental Research of the Technique of Hypothermic Fibrillatory Arrest during Cardiopulmonary Bypass for Myocardial Preservation

目的研究体外循环下低温室颤性停搏方法对心肌的影响。方法选用 1 2条成年健康杂种犬 ,通过对肌钙蛋白Ⅰ (cTnI)、心肌酶谱和ATP含量、心肌超微结构等指标的观察 ,比较在体外循环条件下低温室颤性停搏方法 (实验组 )和传统的晶体停搏液方法 (对照组 )对心肌的损伤程度。结果利用低温室颤性停搏方法测得的cTnI、心肌酶谱和ATP含量等指标明显优于间断灌注晶体停搏液方法 (P <0 .0 1或P <0 .0 5 ) ,对照组心肌超微结构亦显示出较实验组更明显的损害。结论体外循环下低温室颤性停搏方法较传统的晶体停搏液方法具有明显的优势 。

Objective To evaluate the protective effect of hypothermic fibrillatory arrest during cardiopulmonary bypass in dogs.Methods Twelve adult mongrel dogs weighing 16 to 20 kilograms were randomly divided into hypothermic fibrillatory arrest group (experimental group,n=6) and cold crystalloid cardioplegia group (control group,n=6).Ventricular fibrillation was induced with systemic hypothermia to 28℃ and pericardial cooling with 4℃ saline.The release of cTroponin (cTnI),content of myocardial water and intracellular ATP were observed for comparative studies.Results The release of cTnI,content of intracellular ATPand the exudation of myocardium enzymes in experimental group were much lower than that in control group(P&lt;0.01 or P&lt;0.05).Furthermore,the experimental group had less damage on myocardial ultrastructure than that of the control group.Conclusion The technique of hypothermic fibrillatory arrest is superior to the intermittent cold crystalloid cardioplegia for myocardial protection.but the effect of myocardial protection eliminates with the prolongation of fibrillation.