Creatine Kinase (CK)

General Information

Creatine Kinase (CK, CPK) is an enzyme found primarily in the heart and skeletal muscles, and to a lesser extent in the brain. Significant injury to any of these structures will lead to a measurable increase in CK levels. Elevations in CK are found in:

• Myocardial infarction
• Crushing muscular trauma
• Any cardiac or muscle disease, but not myesthenia gravis or multiple sclerosus
• Brain injury
• Hypothyroidism
• Hypokalemia

Once elevated, CK remains elevated for several days, if the injury is acute. If there is on-going injury, the CK will remain elevated indefinitely.

Although still clinically useful in the evaluation of some conditions (e.g. rhabdomyolysis or Duchenne muscular dystrophy), the measurement of CK for myocardial infarction has been replaced in this laboratory by Troponin T measurement.

If you suspect that your patient has had a myocardial infarction, for biochemical conformation please request a Troponin I.