[Enzyme and isoenzyme tests in the diagnosis of myocardial infarct during aortocoronary bypass].

The authors assess the diagnostic value of several enzyme and isozymic tests used in the diagnosis of myocardial infarction in aortocoronary shunting (ACS): the diagnostic sensitivity and specificity, as well as the significance of both positive and negative results, and the diagnostic efficacy of every test have been estimated. Ninety-one patients subjected to autovenous ACS have been examined for the total creatine kinase (CK), lactate dehydrogenase (LDH), aspartate and alanine aminotransferase activities, and for the activities of CK and LDH isozymes. The results evidence a high diagnostic value of CK and LDH isozymes measurements. A comprehensive study of these isozymes is a reliable criterion of the diagnosis of myocardial infarction. If myocardial infarction in ACS is diagnosed on the basis of the total enzymic activities, measurements of the transaminases and LDH are advisable; investigation of CK total activity is of poor informative value.