A heart attack and damage to the heart muscle cause elevated CK-MB levels, according to Healthgrades. CK-MB is found in the heart, so elevated levels of this enzyme generally signify a heart problem.
When CK-MB levels rise, it is because heart muscles are dying. These elevated levels usually occur soon after a heart attack, states Healthgrades. CK-MB levels slowly return to normal a few days after the attack. CK stands for creatine kinase, an enzyme. The other two types of creatine kinase are CK-BB, which is found in the brain, and CK-MM, which is found in the skeletal muscles and the heart.