Abbreviation: CK-MB
An enzyme present in myocardial cells that is released into the serum when myocardial cells are damaged (e.g., acute myocardial infarction, myocarditis). Used as a cardiac biomarker that can help diagnose acute MI, in which levels typically rise 3–12 hours after an infarction, peak at 12–24 hours, and normalize after 2–3 days, making it a good marker for evaluation of myocardial reinfarction as well.