Creatine kinase isoenzyme, abbreviated as CK-MB, mainly exists in the heart muscle, when the heart muscle cells are damaged or necrotic due to some reasons, CK-MB will enter the blood, the higher CK-MB is, the greater the degree and scope of myocardial damage.CK-MB can be seen in high levels in the following diseases: acute myocardial infarction, angina pectoris, heart failure, acute myocarditis, myocardial disease, cardiac trauma, cardiac defibrillation, and so on. CK-MB appears earlier in the blood, so it is a more specific indicator for diagnosing acute infarction. But CK -MB mildly elevated general significance, if greater than the normal high value of more than 2 times to have diagnostic significance, rather than see CK-MB elevated, hastily diagnosed acute infarction or myocarditis.