To determine if you have had a heart attack. However, this test is rarely used now; instead doctors usually request troponin.
If you have chest pain and your CK levels are high.
A blood sample drawn from a vein in the arm.
CK–MB is one of three separate forms of the enzyme creatine kinase (CK). CK–MB is found mostly in heart muscle. It rises when there is any damage to heart muscle cells.
A blood sample is taken by needle from the arm.
No test preparation is needed.
CK–MB levels, along with total CK, may be tested in persons who have chest pain to diagnose whether they have had a heart attack. A high total CK could indicate damage to either the heart or other muscles, but because CK-MB is specific to the heart, a high CK–MB suggests that the damage was due to heart muscle.
CK-MB is rarely used now; it has been replaced by troponin. However, it may be requested with total CK, in persons with chest pain to determine whether the pain is due to a heart attack. It may also be requested in a person with a high CK to determine whether damage is to the heart or other muscles.
If CK-MB is raised, the heart is the muscle which is likely to be damaged. A high CK with a low CK-MB suggests that other muscles were damaged.
If your doctor suspects injury to both heart muscle and other muscles in the body, it may be hard to detect heart injury. Then your doctor may need to request other tests (such as troponin).
Persons whose kidneys have failed can have high CK-MB levels without having had a heart attack. Rarely, long-term muscle disease, low thyroid hormone levels, and alcohol abuse can increase CK-MB, producing changes similar to those seen in a heart attack.
Heart attack means that some of the muscle in your heart has died. A medical term for this is myocardial infarction (MI). Most commonly, a heart attack starts with a kind of heavy pressure or pain in the chest, often extending into the neck or left arm. You may have trouble catching your breath, or you may feel weak and break into a cold sweat.
A heart attack usually occurs because one of the blood vessels (called coronary arteries) that bring blood to your heart muscle is blocked. This happens when a blood clot forms in a blood vessel that is already partially blocked. The partial blockage, which happens gradually over many years, is usually caused by too much fat deposited in the wall of the blood vessel (this is often called hardening of the arteries — the medical term for this is atherosclerosis).
CK, myoglobin, troponin
Tests: CK, troponin
Conditions: Heart attack, Heart disease
RCPA Manual: Creatine kinase MB isoenzyme
Last Review Date: March 25, 2013