CK frequently rises following myocardial infarction and in myocarditis. It may also rise as a result of intervention: coronary angiography and angioplasty, external cardiac massage and DC cardioversion.
Following myocardial infarction:
- total CK: peak value 18-30 hrs; duration 2-5 days; level 5-10 times normal
- CK-MB: peak value 12-24 hrs; duration 1.5-3 days; level variably raised
Note:
- the rise in CK is proportional to the extent of infarction
- total CK is 98% sensitive but only 65-85% specific for acute myocardial infarction; CK-MB is more specific
- prolonged elevations of total CK may represent surgery or infarction. Differentiation of infarction from surgery, particularly cardiac surgery, post-operatively is difficult: total CK and CK-MB rises occur earlier and are smaller for infarction
- repeated infarction may be indicated by a total CK plateau and independent peaks of CK-MB. The latter has a shorter half-life