Clinical significance of the change of electrocardiogram and cardiac markers for myocardial damage after on-pump and off-pump coronary artery bypass grafting

Abstract

Objective To investigate the clinical significance of the changes of electrocardiogram (ECG) and cardiac markers for myocardial damage after on-pump coronary artery bypass grafting (CABG) and off-pump coronary artery bypass grafting (OPCABG). Method Monitoring 25 patients of OPCABG (OPCABG group) and 25 patients of CABG (CABG group) R wave amplitude of V4 and V5 on antorior electrocardiographic lead and simultaneously determining cardiac markers for myocardial damage creatine phosphokinase isoenzyme MB (CPK-MB), tropenin I (cTnI) and heat-shock protein 70 (HSPT0) on different lime. Results R wave amplitude of V4 and V5 on anterior electrocardiographic lead had no significant changes on 0, 6, 18 and 24 hours after OPCABG. On the contrary, R wave amplitude of V4 and V5 on anterior electrocardiographic lead decreased significantly on 0, 6 and 18 hours after CABG (P<0.01), and came back to preoperative values 24 hours after operation. The levels of CPK-MB and cTnI reached its peak and higher significantly for CABG than those for OPCABG on 24 hours after operation, 29.29 μg/L vs 5.98 μg/L and 6.74 μg/L vs 1.91 μg/L respectively. HSP70 increased significantly on 6 hours after operation in two groups, but median of HSP70 was higher significantly in CABG group (11044.5 pmol/L vs1702.0 pmol/L). In the first day after operation the HSP70 peak was correlated significantly with the level of CPK-MB(r=0.370, P<0.01) and cTnI (r=0.458,P<0.01). Conclusions Myocardial damage is significantly alleviated for patients of OPCABG comparing with those of CABG. The HSF70 in circulation may indicate the degree of myocardial damage. Key words: Electrocardiography; . Heat-shock proteins; Coronary artery bypass grafting