If the creatine kinase isoenzyme is more than four times the upper limit of normal, it is indicative of more extensive myocardial cell damage, which means that the creatine kinase isoenzyme is at a risk value. The normal range of creatine kinase isoenzyme varies from 0-6 units to 0-25 units in different laboratories. If the upper limit of normal is exceeded, cardiomyocyte damage may be present. This is usually due to acute myocardial cell damage, such as severe viral myocarditis or acute myocardial infarction, which can lead to necrosis of the myocardial cells, and myocardial enzymes inside the myocardial cells, as well as myocardial markers, are released into the blood leading to elevated lab finger bile. Therefore, a creatine kinase isoenzyme that exceeds four times the upper limit of normal is considered to be a risk value that indicates acute damage to cardiomyocytes.