Sorted By Test Name - Mayo Medical Laboratories

CKMB
82429
CK
8336
Creatine Kinase (CK) MB Isoenzyme, Serum
Clinical Information: There are 3 isoenzymes of creatine kinase (CK)-CKBB, CKMM, and CKMB.
The primary source of CKMB is myocardium although it is also found in skeletal muscle. CKMB levels
increase with myocardial damage. Extreme elevations of CKMB can also be associated with skeletal
muscle cell turnover as in polymyositis and to a lesser degree in rhabdomyolysis. It can also be elevated in
cases of carbon monoxide poisoning, crush injuries, pulmonary embolism, hypothyroidism, and muscular
dystrophy.
Useful For: The serial quantitation of serum creatine kinase MB (CKMB) levels, often performed at
admission and 8-hours, 16-hours, and 24-hours after admission, has traditionally been used as an aid in
the diagnosis of myocardial injury. While CKMB has been replaced by troponin assays in the work-up of
many patients with acute chest pain, CKMB may be useful if the initial troponin determination is
abnormal or if a hospitalized patient has a suspected re-infarction.
Interpretation: Creatine kinase MB (CKMB) levels can be detected within 3 to 8 hours of the onset of
chest pain, peak within 12 to 24 hours, and usually return to baseline levels within 24 to 48 hours.
Reference Values:
Males: