The human enzyme creatine kinase is composed of three isoenzymes MM, MB & BB.
A CKMB > 5 % may be indicative of acute myocardial infarction. Troponin is widely available as a sensitive and specific marker of cardiac damage and CK isoenzyme analysis is now rarely used for this purpose. However, it is useful in cases of persistently raised total CK. It can be used to determine possible heart or muscle pathology and also to exclude the presence of Macro CK (Type 1: immunoglobulin complex, and Type 2: mitochondrial CK).
Please include the Total CK result on the request if available.