Plasma Troponin I (cTnI)

Specimen Required

Heparinized or EDTA Blood

Fasting Required

Purpose of the Test

To see if you have had a heart attack or damage to your heart muscle

When this test is required

The biochemical diagnosis of acute heart muscle damage requires an increase in the troponin concentration with time. If a high-sensitivity cardiac troponin (hs-cTn) test is used, a second specimen is taken in three hours or so after admission. Each laboratory purchases and uses different tests (depending on the manufacturer of the equipment used within the laboratory) which may mean that the timing of the blood samples and the values used to interpret the test will vary between hospitals. It is important that results are interpreted alongside local guidelines.

What the Test Detects

Troponins are proteins in muscle fibres that help to regulate muscle contraction. There are three different troponins: skeletal muscle troponin C (TnC) and two heart muscle troponins, cardiac troponin T (cTnT) and cardiac troponin I (cTnI). When there is damage to heart muscle, cTnI and cTnT are released into the blood.How is the sample collected for testing?A blood sample is taken by needle from a vein in the arm.Is any test preparation needed to ensure the quality of the sample?No test preparation is required.See MoreSee Less

Preparation for the Test

None

Sample Requirements

A blood sample taken from a vein in the arm

Additional Notes

The test is not generally affected by damage to muscles other than the heart, so injections into muscle and accidents or drugs that damage muscle do not normally affect troponin concentrations.

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