Test Overview

Cardiac enzyme studies measure the levels of enzymes and proteins that are linked with injury of the heart muscle. The test checks for the proteins troponin I (TnI) and troponin T (TnT). If your heart muscle is injured, such as from a heart attack, troponin proteins leak out of damaged heart muscle cells, and their levels in the bloodstream rise. The test might also check for an enzyme called creatine kinase (CK).

Because some of these proteins and enzymes are also found in other body tissues, their levels in the blood may rise when those other tissues are damaged. Cardiac enzyme studies must always be compared with your symptoms, your physical examination findings, and other test results.