CK-MB
Also written as: CK-MB — Creatine Kinase-MB
Cardiac enzyme biomarker historically used for myocardial infarction diagnosis, now largely superseded by troponin.
Full Definition
Creatine Kinase-MB (CK-MB) is the cardiac-specific isoform of creatine kinase, an enzyme released when cardiac muscle cells are damaged. CK-MB was historically the primary biomarker for diagnosing myocardial infarction before the development of cardiac troponin assays. While less sensitive and specific than troponin, CK-MB may still be used in certain clinical scenarios, such as detecting reinfarction due to its shorter half-life compared to troponin. CK-MB levels typically rise within 3-6 hours of myocardial injury, peak at 12-24 hours, and normalize within 2-3 days.
Usage
Usage note: Hyphenate as 'CK-MB'; distinguish from total creatine kinase (CK).
In Context
- "CK-MB elevation confirmed myocardial injury despite the patient's normal baseline troponin." — Clinical assessment
- "Serial CK-MB measurements were used to detect reinfarction in the setting of persistently elevated troponin." — Post-procedural monitoring