A troponin test measures the levels troponin T or troponin I proteins in the blood. troponin I has been known in literature as a reliable marker of cardiac muscle tissue injury and is more sensitive and significantly more specific in diagnosis of the myocardial infarction. These proteins are released when the heart muscle has been damaged, such as occurs with a heart attack or to distinguish signs and symptoms such as Chest pain. Testing is also done to evaluate people with angina if their signs and symptoms worsen. It is preferred test for suspected heart attack. The more damage there is to the heart, the greater the amount of troponin T and I there will be in the blood.