Serum or Plasma *S. *tropomyosin* (Cardiac Troponin I) – Quantitative
This test measures the levels of cardiac troponin I, a protein released when heart muscle is damaged.
["A key marker for detecting heart injury, often used to diagnose conditions like a heart attack."]
Key facts at a glance
- LOINC
- 10098-2
- Short code
- ST Slope L-II
- Synonyms
- ST Slope L-II
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ekg
- 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 Cardiac Troponin I Used For?
Cardiac troponin I helps doctors determine if you’ve experienced heart muscle damage, such as from a heart attack, severe heart strain, or other cardiac events. It’s especially important for evaluating symptoms like chest pain, shortness of breath, or unusual fatigue that may signal a heart issue.
How Is the Test Performed?
A small blood sample is taken from a vein, usually in your arm. The sample is sent to a lab for analysis using an immunoassay method to detect troponin I levels.
What Are Possible Results?
Results are reported in arbitrary units per milliliter (U/mL) or mass concentration units. Elevated levels may indicate recent or ongoing heart damage, while normal levels suggest no significant heart injury.
When Might You Need This Test?
Your doctor may order this test if you have symptoms like chest pain, irregular heartbeat, shortness of breath, or if you’ve been diagnosed with conditions that put your heart at risk, such as heart disease or high blood pressure.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Why It Matters
Short name
Cardiac Troponin I (Serum/Plasma)
Frequently asked questions
Cardiac troponin I is highly specific to heart muscle cells. Elevated levels are a strong indicator of myocardial infarction (heart attack), acute coronary syndrome, or other cardiac emergencies. It helps doctors assess severity, guide treatment, and monitor recovery.
A positive result (elevated troponin I) suggests recent heart damage, which may require urgent medical attention. Your doctor will review your symptoms, medical history, and other test results to determine the next steps.
Troponin levels can begin rising within hours of a heart attack, peaking around 1–2 days, and may stay elevated for several days. Your doctor may order repeat tests to track changes over time.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 16, 2026. · Read our editorial policy