Cardiac isoenzyme methodology and the diagnosis of acute myocardial infarction.

In view of rapidly evolving technology, a thorough appreciation of the subtle nuances of isoenzyme analysis is mandatory in the selection of appropriate methods. The effectiveness of a given laboratory in diagnosing and monitoring ischemic heart disease is related to the sensitivity and specificity of the methods employed. The occurrence of variants of creatine kinase will decrease the specificity of some isoenzyme methods. This study compares the sensitivity and efficiency of four methods for CK-MB and two methods for LD isoenzymes currently available to the laboratory community. The significance of isoenzyme patterns in confirming myocardial infarction was compared with other cardiac diagnostic parameters to determine the most effective laboratory methods. The selection of methods for measurement of cardiac isoenzymes will determine the effectiveness of the laboratory in the diagnosis of myocardial infarction.