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Cardiac
Troponin (cTnI / hs-cTn)
Normal range
< 0.04 ng/mL (conventional; hs assays lab-specific)
SI: lab-specific
Critical high: any significant rise/fall pattern
☎ When to call
Any new elevation with chest pain/ECG changes — this is an MI pathway activation, not a routine result. Rising serial troponins: call with the trend and current symptoms.
What you do
- Serial draws on time — the PATTERN diagnoses MI, a single value doesn't
- New elevation: 12-lead ECG now, compare to prior; chest pain assessment
- Renal patients run chronically elevated — the delta matters, not the absolute
Causes of HIGH troponin
Causes of LOW troponin
Source: Pagana, Mosby's Manual of Diagnostic and Laboratory Tests, 7th ed.; AHA/ACC chest pain guidelineReference only — verify against your facility's policy.
