Cardiac Markers

Troponin I

Q: What is the normal range for Troponin I?

The standard teaching reference range for Troponin I is < 0.04 (assay-dependent) ng/mL in conventional units, or < 0.04 µg/L in SI units. This value is measured in serum or plasma. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.

Q: What causes a high Troponin I?

Common causes of a high Troponin I: Acute myocardial infarction; Myocarditis; Heart failure or PE; Renal failure (chronic elevation).

Q: What injury threshold is taught for Troponin I?

For Troponin I, the commonly taught injury threshold is: Any elevation above the 99th percentile signals myocardial injury.

Normal range < 0.04 (assay-dependent) ng/mL (< 0.04 µg/L SI). Specimen: Serum or plasma.

Also known as: cTnI, cardiac troponin I.

< 0.04 (assay-dependent) ng/mLInjury threshold: read below

Reference range

This result is reported qualitatively or as a one-sided threshold rather than a two-sided numeric band.

Combined adult band. LabVals does not publish separate men's, women's, or pediatric ranges for Troponin I; those can be narrower than the band shown.

Troponin I reference range, specimen, and conversion details
Specimen	Serum or plasma
Conventional range	< 0.04 (assay-dependent) ng/mL
SI range	< 0.04 µg/L
Conversion factor	×1 (conventional → SI)
Injury threshold	Any elevation above the 99th percentile signals myocardial injury
Panel	Cardiac Markers

Convert any Troponin I result between units on the unit converter.

What is the normal range for Troponin I?

The standard teaching reference range for Troponin I is < 0.04 (assay-dependent) ng/mL in conventional units, or < 0.04 µg/L in SI units. This value is measured in serum or plasma.

What injury threshold is taught for Troponin I?

For Troponin I, the commonly taught injury threshold is: Any elevation above the 99th percentile signals myocardial injury.

Source: Adult reference values compiled from Pagana & Pagana, Mosby's Diagnostic and Laboratory Test Reference, and Fischbach & Dunning, A Manual of Laboratory and Diagnostic Tests. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.

Above the range

What causes a high Troponin I?

Acute myocardial infarction
Myocarditis
Heart failure or PE
Renal failure (chronic elevation)

What causes a high Troponin I? Read as its own page

At the bedside

Nursing considerations

The preferred marker for MI - highly cardiac-specific.
Draw serial troponins (e.g. 0 and 3-6 h) to detect a rise-and-fall pattern.
Thresholds differ by assay, especially high-sensitivity troponin.

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