Creatine phosphokinase and its isoenzymes mainly exist in skeletal muscle and myocardium, and also exist in a small amount in brain tissue, which is an enzyme involved in energy metabolism in the body. The simultaneous increase of both is an important diagnostic index of acute myocardial infarction, which is mainly used to diagnose myocardial infarction in clinic. The blood of patients with myocardial infarction began to rise 2-4 hours after onset. In addition, creatine phosphokinase will also increase after skeletal muscle injury and strenuous exercise. You exercise the day before the examination and feel sore on the day of the examination, which is estimated to be closely related to the increase of creatine phosphokinase; A cold may cause myocarditis. Creatine phosphokinase and its isoenzyme should increase at the same time, but your isoenzyme index is normal, so it is estimated that it is not myocarditis.