Creatine kinase isoenzyme (CK-MB) is a clinical biochemical marker for the diagnosis of myocardial infarction. When myocardial infarction occurs, creatine kinase rises within 6 hours of onset, reaches a peak within 24 hours, and returns to normal within 3-4 days . CK-MB can reflect myocardial damage,.It has important clinical value in the diagnosis and prognosis evaluation of myocardial infarction.