Creatine Kinase (CK) also referred to as creatine phosphokinase (CPK) or phosphocreatine kinase is an enzyme in the body that causes the phosphorylation of creatine. Creatine kinase (CK) is found in the skeletal muscle, cardiac muscle, brain, bladder, stomach and colon. The CPK levels can be elevated by muscle diseases or muscle necrosis. CPK leaks into the blood when a muscles tissue is damaged, and as such high levels of CPK is indicative of stress or injury to the heart or other muscles.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 myocardium's 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.