Examinations
Examinations
Troponins are a group of proteins found in skeletal and cardiac muscle fibers. There are three types of troponins: Troponin C (TnC), Troponin T (TnT), and Troponin I (TnI). Together, these proteins regulate muscle contraction. However, Troponin T (cTnT) and Troponin I (cTnI) are found exclusively in the heart muscle (myocardium), making them cardiac-specific biomarkers.
Why is Troponin I Important?
- Under normal conditions, cardiac troponins are not present in the bloodstream.
- When heart muscle cells are damaged (e.g., during a heart attack), Troponin I is released into the blood.
- The greater the heart damage, the higher the troponin level in the blood.
- After a myocardial infarction (heart attack), troponin levels begin to rise within 3–4 hours, peak at 12–24 hours, and remain elevated for 10–14 days.
- Sample: Blood drawn from a vein.
- Fasting is not required, but the test should be taken at least 2 hours after a light meal
- Suspected myocardial infarction (heart attack).
- Differentiation between cardiac and non-cardiac causes of chest pain.
- Early detection of heart muscle injury.
What Does an Elevated Troponin Level Indicate?
Since troponin is normally undetectable in the blood, an increase in its level indicates cardiac muscle damage.
If troponin levels are significantly high, the patient has likely experienced a heart attack or another serious cardiac condition.
Troponin levels can remain elevated for 1–2 weeks after a heart attack.
Cardiac-Related Causes of Elevated Troponin I
- Myocardial infarction (heart attack)
- Acute or chronic heart failure
- Tachycardia (abnormally fast heart rate)
- Acute inflammatory myocarditis
- Aortic valve disease
- Hypertrophic cardiomyopathy (thickened heart muscle)
- Bradyarrhythmia (abnormally slow heart rhythm)