Role of MB isoforms (isomers) in the early diagnosis of acute myocardial infarction.

In addition to electrocardiogram (ECG), analysis of creatinine phosphokinase (CPK), lactate dehydrogenase (LDH) and their isoenzymes is commonly employed to diagnose acute myocardial infarction (AMI). The aim of this study was to observe the efficiency of isomers of CPK for early diagnosis of AMI. ECG, though useful in many ways, is not 100% sensitive. The drawback involved with CPK and LDH isoenzymes is the time lag factor in diagnosing AMI early enough for interventional therapy. Recently the subunits of these isoenzymes, namely MM and now the MB isomers are being tested for their effectiveness in the early diagnosis of AMI. In our experience MB isomers were found to be accurate markers in the early diagnosis of AMI. They were especially valuable in diagnosing myocardial infarction not detectable by ECG in cases such as non-Q AMI, cardiomyopathy, and bundle branch block among other such cases.