CK-MB is found primarily in cardiac tissue.1 CK-MB can be detected at elevated concentrations following myocardial damage. Abnormal plasma CK-MB concentrations are often associated with ischemia or necrotic heart injury. The increase in CK-MB concentration is often evident within 3 to 6 hours following onset of chest pain, reaching peak concentrations within 12 to 24 hours. CK-MB concentrations will generally return to normal within 24 to 72 hours.2 The determination of CK-MB is most beneficial when samples have been drawn at appropriate time intervals post onset of chest pain.
1 Lang H, ed. Creatine kinase isoenzymes: pathophysiology and clinical application. Berlin: Springer-Verlag, 1981.
2 Roberts R. Heart Lung 1981;10(3): 486-506