Creatine Kinase MB (CK-MB) details
What Creatine Kinase MB (CK-MB) shows
CK-MB is a heart-specific form (isoenzyme) of creatine kinase, an enzyme that rises in the blood when heart muscle is damaged. It was historically one of the primary blood tests used to diagnose a heart attack, since it rises within a few hours of heart muscle injury and returns to normal within a couple of days, which also made it useful for detecting a second heart attack occurring soon after a first one. It's now largely been superseded by high-sensitivity troponin tests, which are more sensitive and specific for heart muscle damage, though CK-MB is still used in some settings, including to help assess whether a heart attack is very recent versus in the more distant past.
Tests that include Creatine Kinase MB (CK-MB)
The Creatine Kinase Isoenzymes test is used to confirm or rule out the diagnosis of acute myocardial infarction, assess its severity, and monitor the patient's condition.
- Creatine Kinase BB (CK-BB) A form (isoenzyme) of creatine kinase found mainly in brain tissue. Less commonly used clinically than the heart- and muscle-specific forms.
- Creatine Kinase MB (CK-MB) A form of creatine kinase found mainly in heart muscle. Historically used to help detect heart muscle damage, such as a heart attack.
- Creatine Kinase MM (CK-MM) A form of creatine kinase found mainly in skeletal muscle. Elevated levels typically reflect muscle injury or strenuous exercise rather than heart damage.
- Creatine Kinase An enzyme found in muscle, heart, and brain tissue. Elevated levels typically indicate muscle damage, from injury, intense exercise, or certain medical conditions.
- Macro CK Type 1 A less common, larger form of creatine kinase bound to an antibody. Usually a benign finding rather than a sign of tissue damage, but can cause a persistently elevated CK result.
- Macro CK Type 2 A less common, larger form of creatine kinase, typically seen in people who are critically ill; unlike Type 1, it can reflect a more serious underlying condition.
This test measures creatine kinase (CK), an enzyme found primarily in striated muscle and heart tissue, and may be useful in assessing muscle damage. Total CK and fractions of CK isoenzymes are reported. CK is a dimeric enzyme composed of either 2 B subunits (CK-BB), 2 M subunits (CK-MM), or an M and a B subunit (CK-MB). CK-MM is the primary isoenzyme found in the skeletal muscle and heart tissue. CK-BB is mainly found in the brain and smooth muscle of gastrointestinal tract and urinary bladder. CK-MB is mainly found in the heart with a small amount in skeletal muscle [1].
- Creatine Kinase BB (CK-BB) A form (isoenzyme) of creatine kinase found mainly in brain tissue. Less commonly used clinically than the heart- and muscle-specific forms.
- Creatine Kinase MB (CK-MB) A form of creatine kinase found mainly in heart muscle. Historically used to help detect heart muscle damage, such as a heart attack.
- Creatine Kinase MM (CK-MM) A form of creatine kinase found mainly in skeletal muscle. Elevated levels typically reflect muscle injury or strenuous exercise rather than heart damage.
- Creatine Kinase An enzyme found in muscle, heart, and brain tissue. Elevated levels typically indicate muscle damage, from injury, intense exercise, or certain medical conditions.
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