Specificity of serum creatine kinase isoenzymes in diagnosis of acute myocardial infarction.

A study of the diagnostic value of serum creatine kinase (CK) isoenzymes showed that MB isoenzyme, which characterizes heart tissue, was a specific and sensitive indicator of acute myocardial infarction. In cases where the clinical picture was complicated by ventricular tachycardia, severe congestive failure, shock, or resuscitation procedures heart, liver, and muscle enzymes were increased. There was also an increase in lactate dehydrogenase isoenzyme values in these cases; indeed, the only enzyme test that correlated well with electrocardiographic and necropsy findings was the MB isoenzyme.