Cardiac enzyme. Troponin t is an enzyme in heart muscle cells that is specific to heart muscle so the term "cardiac specific troponin t" is redundant. Normally, almost all of the troponin t we own is inside of the heart muscle cells with almost none (an immeasurably small amount) is in our blood. When the heart is injured, some troponin leaks into the blood where it becomes measurable.
A biomarker. Measurement of troponin t is used to help make the diagnosis of myocardial infarction (heart attack). The chemical leaks from damaged heart muscle and confirms injury to the heart. A new assay called highly sensitive troponin is now available and is 10 times more sensitive and increases the speed and accuracy of the diagnosis. If the result is negative 3 hours after chest pain, mi is unlikely.