Serial determinations of serum enzymes following Aorta-Coronary bypass surgery and acute myocardial infarction.

Abstract

Serial determinations of serum creatine kinase (CK), cardiospecific isoenzyme of CK (CK-MB), glutamic oxaloacetic transaminase (GOT) and alpha-hydroxybutyrlate dehydrogenase (HBD) were made in 29 consecutive patients undergoing aorta-coronary (AC) bypass grafting, and the results were compared with those in 31 patients with acute myocardial infarction (AMI). Postoperatively all patients had an uneventful postoperative course and there was no evidence of AMI. The time course of enzyme activity following surgery was characterized by shortening of peak activity time of all enzymes except CK, rapid disappearance of CK-MB and prolonged normalization of GOT and HBD. Peak activities of CK, CK-MB, GOT and HBD in AC bypass patients were 801 .+-. 77, 46 .+-. 6, 100 .+-. 9 and 718 .+-. 32 IU (mean .+-. SEM), respectively, which were equivalent to 46%, 12%, 22% and 47% of those in AMI. The degree of postoperative CK-MB elevation was influenced by the duration of the operation and the extracorporeal circulation, and the number of grafts bypassed. The peak CK-MB activity did not correlate with the CK peak. The ratio of CK-MB to CK was much smaller in AC bypass than in AMI (6.5 .+-. 1.8 vs. 20.1 .+-. 1.4%). Serum enzyme elevations after AC bypass surgery largely reflected enzyme release from the skeletal muscle rather than the myocardium.