心肌肌钙蛋白Ⅰ对体外循环期心肌损伤的判定价值

Application of cardiac troponin I to the diagnosis of myocardial injury following CPB

目的 探讨心肌肌钙蛋白I(cTnI)对体外循环期心肌损伤的判定价值。方法 2 0例心内直视手术病人随机分为两组 ,冷晶体停跳组 (组Ⅰ ) ,冷氧合血停跳组 (组Ⅱ ) ,每组 10例 ,分别于围术期多个时点采取中心静脉血 ,测定血清cTnI、CK及CK MB的水平 ,并观察缺血前后心肌超微结构变化。结果 术前两组的cTnI、CK及CK MB水平均在正常范围 ,开放主动脉后 1h至术后 2 4h达峰值 ,其后缓慢下降。术后 2 4h、48h冷氧合血停跳组cTnI水平明显低于冷晶体停跳组 (P <0 .0 5 ) ,CK MB在开放主动脉后 1h冷氧合血停跳组低于冷晶体停跳组。cTnI峰值浓度与主动脉阻时间呈直线正相关。结论 cTnI判定心内直视手术围术期心肌损伤的敏感性及特异性明显优于CK、CK MB ,对围术期心肌缺血损伤的诊断。

Objective To evaluate the clinical value of cardiac troponin I(cTnI) in the diagnosis of myocardial ischemic injury.Methods Twenty patients were randomly divided into two groups: group I (cold crystalloid cardioplegia, n=10) and group Ⅱ (cold blood cardioplegia, n=10). The central venous blood samples were taken at various times during perioperation to measure the serum levels of cTnI,CK MB and CK . Myocardial samples were obtained 10 min before aorta clamping and 30 min after aotra unclamping, to observe myocardial ultrastructure .Results cTnI,CK and CK MB levels were normal before operation, increased markablely following aotra unclamping ,reached the peak 1 h after aorta unclamping to 24 h after operation, and decreased progressively to be normal in two groups. The serum cTnI level was significantly lower in group Ⅱ than that in group Ⅰ 24 h and 48 h after operation. The serum CK MB activity was lower in group Ⅱ than that in group Ⅰ 1 h after aorta unclamping. There was positive significant correlation between aorta cross clamping time and cTnI peak level.Conclusions cTnI can be used to evaluate the degree of myocardial injury and myocardial protective effect in open heart surgery during CPB. As indicators for reflecting the myocardial injury, the sensitivity and specificity of cTnI are more valuable than those of myocardial enzymes.