Evaluation of myocardial infarction and/or skeletal muscle damage. The creatine kinase isoenzyme test separates the major isoenzymes of creatine kinase (CK-MM (muscle), CK-MB (specific for cardiac muscle), and CK-BB (found in brain, prostate, gut, lung, bladder, uterus, placenta, and thyroid) by electrophoresis. The test provides the percentages of each in relationship to total creatine kinase. The test provides information on recent muscle damage (CK-MM and CK-MB), providing specific information about possible cardiac muscle damage (CK-MB) due to myocardial infarction.