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Creatine Kinase-MB, CPK-MB


CK (creatine kinase) is an enzyme (protein) found in several tissues, including muscles and the heart. Depending on the tissue, different forms of CK are present: CK-MM, primarily present in skeletal muscles, CK-MB with the highest percentage in the heart, and CK-BB, which comes from the brain and smooth muscle, such as the intestinal walls. The specific CK-MB assay is used primarily to diagnose myocardial infarction when total CK levels are high and a troponin assay is not available. CK-MB appears in the blood 3 to 6 hours after the onset of the infarction. It reaches a maximum level in 12 to 24 hours, before returning to normal in 48 to 72 hours. If a second infarction occurs in the interim, the elevated CK-MB level will be prolonged.

A high CK-MB usually reflects a heart muscle injury (infarction, inflammation, trauma, surgery or heart biopsy). Intense muscle exercise can sometimes cause abnormal CK-MB because skeletal muscles contain approximately 7% CK MB. More rarely, kidney failure, chronic muscle disease or hypothyroidism can also increase CK-MB.

Term of the Week

Hot zone

A hot zone is a section of a facility (sometimes an entire facility or even a city district) where there is a high risk of contamination by patients with an infectious disease. All individuals entering a hot zone must respect appropriate protective measures. By analogy, “cold zone” and “warm zone” are used to refer to areas where there is no infected individual or only individuals suspected of having an infection.