Troponin
The enzymes troponin I and troponin T are normal proteins important in the contractile apparatus of the cardiac myocyte.
They are released into the circulation about 3-4 hours after myocardial infarction and are still detectable for 10 days afterwards.
The long half-life allows for the late diagnosis of myocardial infarction, however makes it difficult to detect re-infarction.
There are a number causes of troponin elevation not related to myocardial infarction, however troponin elevation is much more sensitive and specific than myoglobin and even CK.
