目的:探讨围术期静脉滴注左-卡尼汀对冠状动脉旁路移植术患者心肌缺血再灌注损伤的影响。方法:回顾性分析2015年1月至2017年12月在西安交通大学第一附属医院心血管外科60例行体外循环下冠状动脉旁路移植手术患者的临床资料。按照围术期是否使用左-卡尼汀将患者分为对照组和观察组。两组患者围术期除常规给药外，观察组予静脉滴注左-卡尼汀处理，对照组予静脉滴注等量生理盐水处理。两组患者均于术前1 h及主动脉开放后2、6、24、72 h采静脉血，观察并比较血清心肌酶[谷草转氨酶(AST)、乳酸脱氢酶(LDH)、肌酸激酶(CK)和肌酸激酶同功酶(CK-MB)]水平。评价两组患者术前和术后左心功能指标[每搏输出量(SV)、心脏左室舒张内径(LVDD)、每分输出量(CO)、射血分数(LVEF)]。结果:两组患者血清AST、LDH、CK和CK-MB水平于主动脉开放后均明显升高(n P<0.05)。其中血清AST、LDH和CK水平于主动脉开放后24 h达高峰，且观察组血清CK、AST和LDH水平在主动脉开放后各时间点均低于对照组(n P<0.05)。观察组血清CK-MB水平于主动脉开放后6 h达高峰，而对照组则在主动脉开放后24 h达高峰，且观察组血清CK-MB水平在主动脉开放后各时间点均低于对照组(n P0.05)，术后观察组SV、CO和LVEF明显高于对照组，而LVDD明显小于对照组，差异均有统计学意义(n P<0.05)。n 结论:左-卡尼汀可降低体外循环下冠状动脉旁路移植术患者的血清心肌酶水平，对患者心肌缺血再灌注损伤起到一定的保护作用。“,”Objective:To investigate the effect of L-carnitine on myocardial ischemia-reperfusion injury in patients undergoing coronary artery bypass grafting (CABG) operation.Methods:The clinical data of 60 patients who had underwent CABG under extracorporeal circulation in Department of Cardiovascular Surgery, the First Affiliated Hospital of Medical College of Xi′an Jiaotong University from January 2015 to December 2017 was retrospectively analyzed. L-carnitine was infused into the patients in the observation group while the equal amount of normal saline was given to the patients in the control group during perioperative period. Venous blood was collected from each patient 1 hour before the surgery and at 2, 6, 24 and 72 hours after unclamping the aorta, then serum levels of aspartate aminotransferase (AST), lactic acid dehydrogenase (LDH), creatine kinase (CK), and creatine kinase-MB isozyme (CK-MB) were detected. Additionally, cardiac function indices including stroke volume (SV), left ventricular diastolic diameter (LVDD), cardiac output (CO), Left ventricular ejection fraction (lVEF) were compared between the two group patients before the surgery and 6 days after operation.Results:Compared with before the operation, the levels of serum enzymes were all significantly increased after unclamping the aorta. The levels of serum AST, LDH and CK reached their peak at 24 hours after unclamping the aorta. Notably, the levels of serum AST, LDH and CK in the experimental group were lower than that in the control group at each time point after unclamping the aorta (n P<0.05). For serum CK-MB, the level in the experimental group reached its peak at 6 hours after unclamping the aorta, while the peak value was observed at 24 hours after unclamping the aorta in the control group. The level of CK-MB in the experimental group was significantly decreased compared with the control group at each time point after unclamping the aorta (n P0.05). The levels of SV, CO and LVEF in the experimental group were significantly increased while the level of LVDD was obviously decreased compared to that in the control group after the operation (n P<0.05).n Conclusions:L-carnitine has protective effects on myocardial ischemia-reperfusion injury in patients undergoing CABG operation under cardiopulmonary bypass, with reducing serum levels of myocardial enzyme in these patients.