Cardiac-Specific Troponin I and T

This test is used to determine if you have had a heart attack or injury to heart muscle. It is generally done 2-3 times during a 12 to 16 hour period if you are having chest pain or other symptoms that may be due to a heart attack. This test measures the concentration of cardiac-specific troponin in your blood. Troponin is a family of proteins found in skeletal and heart muscle fibers; it helps muscles contract. There are three forms of troponin: C, I, and T. Cardiac troponin I and T are different enough from the troponin I and T found in skeletal muscle that they can be specifically tested for. These types of troponin are normally present in very small quantities in the blood. When there is damage to heart muscle cells, cardiac troponin I and T are released into circulation. The more damage there is, the greater the concentration of troponin I and T. When a patient has a heart attack, levels of troponin can become elevated in the blood within 3 or 4 hours after injury and may remain elevated for 10 to 14 days.

PREPARATION FOR TEST

A blood sample is obtained by inserting a needle into a vein in the arm.

NORMAL FINDINGS

  • Cardiac troponin T: less than 0.1 ng/mL (<0.1 mcg/L)

  • Cardiac troponin I: less than 0.03 ng/mL (<0.03 mcg/L)

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.

MEANING OF TEST

Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.

OBTAINING THE TEST RESULTS

It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.