冠状动脉旁路移植术围术期心肌肌钙蛋白I动态变化

目的　观察心肌肌钙蛋白I(cTnI)和CK -MB在冠状动脉旁路移植术 (CABG)围术期变化 ,以判断心肌损伤状况。方法　 19例CABG病人 ,其中 3例同时行左室室壁瘤切除。平均体外循环时间12 1min ,阻断升主动脉 5 6min。灌注冷血停跳液保护心肌 ,平均每例搭桥 3 2支。围术期 2 0个时间点取静脉血标本 ,留血浆测cTnI和CK MB。术前及术后第 7d作标准 12导联心电图 (ECG)。结果　cTnI术前 5例升高者 ,停机后全部升高 ,第 8h达高峰 ,术后第 7d有 7例 (36 8% )仍高于正常 ;CK MB阻断升主动脉前正常 ,停机后升高 ,第 6h达高峰 ,术后第 2d全部恢复正常 ;2例发生围术期心梗 (PMI)者 ,整个围术期cTnI高于无PMI者 ;cTnI阻断升主动脉前已升高者 ,术后升高更显著。结论　cTnI与CK MB在CABG术后变化规律相似 ,但cTnI高于正常的持续时间长于CK MB ,有利于回顾性诊断 ;若阻断升主动脉前cTnI已升高 ,术后水平更高 ;cTnI诊断心肌损伤敏感性高于CK -MB。

Preliminary study on perioperative release of cardiac troponin I in coronary artery bypass grafting

Objective: To investigate the perioperative release of cardiac troponin I(cTnI) and CK-MB and their efficacy in diagnosing myocardial injury in coronary artery bypass grafting (CABG). Methods: Nineteen CABGs for unstable angina pectoris (UAP), including 3 concomitant left ventricular aneurysm resection, were performed. The average number of grafts was 3.2(2-5) per patient, mean CPB time was 121 minutes and aorta-clamping time was 56 minutes. Cold blood cardioplegic solution was infused either through a double-lumen needle in the ascending aorta or through a retrograde coronary sinus catheter introduced via the lateral wall of right atrium or through grafts. Venous blood samples were taken at 20 different time intervals for determining of cTnI and CK-MB concentration. In all patients' ECG recordings was obtained preoperatively and on the 7th postoperative day. Results: cTnI increased significantly in 5 (26.3%) before operation. After the patients were weaned from CPB, cTnI increased in all samples, reaching peak value at 8 hour and then decreasing progressively in 7 patients(36.8%), but still higher than the baseline value until the 7th postoperative day. The time course of CK-MB was similar to that of cTnI with the exception of returning to normal just 2 days after operation. cTnI in patients with postoperative myocardial infarction (PMI) was significantly higher than that of non-PMI patients during the perioperative period. Conclusion: cTnI increase in all patients after CPB reflects the inevitable myocardial damage. cTnI is of larger diagnostic time window and higher sensitivity in detecting myocardial damage than CK-MB, indicating its application in retrospective diagnosis. Patients with increased cTnI before operation tend to be more liable to PMI.