心脏围手术期心肌肌钙蛋白T临床观察

目的评价心肌肌钙蛋白T(cTnT)作为判断心肌损伤指标的敏感性和特异性。方法对78例心脏手术患者(60例瓣膜替换术、18例动脉导管未闭和心包炎)进行分析。60例患者于术前和主动脉开放后2h测定血液中cTnT，进行阻断时间和cTnT的相关和回归分析；其中20例瓣膜手术患者与18例动脉导管结扎和心包剥脱术患者分别于术前，关胸后1,2,24和48h记录心电图，并抽血测定肌酸激酶(CK)、肌酸激酶-MB(CK-MB)和cTnT。结果60例瓣膜手术患者术前cTnT均在正常值范围内，主动脉开放后2h时，阻断时间和cTnT的相关系数为r=0.875(P＜0.01)，回归方程为Y=0.019X-0.026；其中20例瓣膜手术患者心脏经过阻断后，心电图有缺血性改变，周围血液中的CK、CK-MB和cTnT均有明显升高，分别在关胸后2h达到高峰，数值分别为术前的12.6、9.2和257倍；18例行动脉导管结扎和心包剥脱术的患者术前和关胸后的心电图和血液中的cTnT均正常，CK和CK-MB除2例心包炎患者关胸后出现明显变化外，余均未见改变。结论cTnT作为判断心肌损伤的指标，其敏感性和特异性良好，且均优于CK和CK-MB。

Clinical observation of myocardial troponin T during perioperative cardiac surgery

Objective To evaluate the sensitivity and specificity of cardiac Troponin T(cTnT) as a marker of myocardial injury. Methods 78 patients were included (valve replacement in 60 and patent ductus arteriosus (PDA)and pericarditis in 18 ). Of the 60 patients, blood samples were taken for measurement of the concentrations of cTnT before operation and 2 hours after unclamping aorta, and analysed the correlation coefficient between cTnT and the period of aortic clamping. Among them, 20 patients were candidates of valve replacement and 18 PDA and pericarditis had their blood samples taken before operation,and 1,2,24 and 48 hours after closure of thorax for measurement of concentrations of CK、CK-MB and TnT,together with ECG recording. Results Of the 60 patients, concentrations of cTnT before operation were normal; 2 hours after aortic unclamping, the correlation coefficient between cTnT and aortic clamping was r = 0.873( P＜0.01), the regression analysis showed Y = 0. 019X-0. 026. Of the 20 patients, ECG showed the myocardium was ischemic; CK、CK-MB and cTnT all rose significantly, reaching the peak after closure of thorax. Of the 18 patients, the ECG and cTnT before operation and after closure of thorax were normal; except 2 patients with pericarditis. Conclusion As a marker of myocardial injury, cTnT is better than CK and CK-MB both in sensitivity and specificity.