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Cardiac Troponin I, Serum or Plasma Mass Concentration

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of troponin I, a protein released when heart muscle is damaged, often due to a heart attack.

Quick summary

["Troponin I helps doctors assess heart injury and guide treatment decisions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
101446-3
Short code
CK MB SerPl IA-sCnc
Synonyms
CK MB SerPl IA-sCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
22
Ref high
198
Critical range
— – 10000 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82553
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is Troponin I Used For?

Troponin I is primarily used to diagnose and monitor conditions affecting the heart, such as heart attacks (myocardial infarction). It can also help determine the severity of heart damage or guide treatment plans for conditions like heart failure or myocarditis.

How Is the Test Performed?

A blood sample is taken from a vein, usually in your arm. The sample is sent to a lab where it is analyzed to measure troponin I levels. The test is typically done quickly, often within hours of drawing the blood.

Why Might You Need This Test?

You may need a troponin I test if you have symptoms like chest pain, shortness of breath, or other signs of heart problems. Doctors also use it to check for heart damage after a suspected heart attack or during ongoing heart conditions.

What Are Common Symptoms?

Common symptoms that might lead to this test include chest pain or pressure, pain spreading to your arms, jaw, or back, shortness of breath, nausea, or dizziness. Always seek medical attention if you experience these symptoms.

Reference range

Adult males: 22-198 U/L; Females: 22-198 U/LN/A

Specimen: serum

No special preparation required. Inform provider of any chest pain or symptoms.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Troponin I (cTnI)

Frequently asked questions

What does a high troponin I level mean?
A high troponin I level often indicates heart muscle damage, which can be caused by a heart attack, severe heart strain, or other conditions like myocarditis. Your doctor will discuss the results in the context of your symptoms and medical history.
How long does it take to get results?
Results are usually available within a few hours to a couple of days, depending on lab processes and your healthcare provider’s workflow. Your doctor will contact you with the results once they are ready.
Can troponin I levels change over time?
Yes, troponin I levels can rise and fall depending on the severity and duration of heart damage. Your doctor may order follow-up tests to monitor changes over time, especially if you have ongoing heart conditions or symptoms.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy