A sensitive and specific diagnostic to identify an acute myocardial infarction is creatine phosphokinase-MB. The enzyme phosphocreatine kinase has two forms such as the isoenzymes CKM and CKB which CPK-MB evaluates in blood levels and comparatively limits. The ratio of CK-MB1 and CK-MB2 isoforms can be measured relatively precisely and easily. The Creatine Phosphokinase-MB test can identify the myocardiums B subunit isoforms. Even when high after irreversible myocardial injury creatine phosphokinase-MB is beneficial as one of the finest diagnostic tests for MI. With any therapeutic intervention that lessens myocardial damage it is simpler to recognise a patient who has acute coronary syndrome.