All of the following enzymes are increased in myocardial infarction, EXCEPT:

In MI, total LDH activity is increased, while H4 iso-enzymes is increased 5-10 times more. The magnitude of the peak value will be roughly propoional to the size of myocardial infarct. CK value in serum is increased in myocardial infarction. The CK level stas to rise within 3-6 hours of infarction. Therefore CK estimation is very useful to detect early cases. The CK level is not increased in hemolysis or in congestive hea failure and therefore CK has an advantage over LDH. Normal level of AST is 8-20U/L. The level is significantly elevated in Myocardial infarction. Isocitrate dehydrogenase is not elevated in myocardial infarction. Must know: The enzymes routinely elevated in myocardial infarction are: Creatine kinase(CK) Lactate dehydrogenase(LDH) Aspaate aminotransferase(AST) Cardiac troponin I(CTI) and Cardiac troponin T(CTT) Brain Natriuretic peptide(BNP). It is reliable marker of congestive cardiac failure. Ref: Textbook of Biochemistry By DM Vasudevan, 5th Ed Page 54-55