The troponin test is done to assess the amount of troponin T and troponin I proteins in the blood, which are released when there is an injury to the heart muscle, such as when a heart attack occurs, for example. The greater the damage to the heart, the greater the amount of these proteins in the blood.
Thus, in healthy people, the troponin test does not normally identify the presence of these proteins in the blood, being considered a negative result. The normal values of troponin in the blood are:
- Troponin T: 0.0 to 0.04 ng / mLTroponin I: 0.0 to 0.1 ng / mL
In some cases, this test may also be ordered with other blood tests, such as the measurement of myoglobin or creatinophosphokinase (CPK). Understand what the CPK exam is for.
The test is done from a blood sample that is sent to the laboratory for analysis. For this type of clinical analysis, no preparation is necessary, such as fasting or avoiding medications.
When to take the exam
This test is usually ordered by the doctor when there is a suspicion that a heart attack has occurred, such as when symptoms such as severe chest pain, difficulty breathing or tingling in the left arm, for example. In these cases, the test is also repeated 6 and 24 hours after the first test. Check for other signs that may indicate a heart attack.
Troponin is the main biochemical marker used to confirm infarction. Its concentration in the blood begins to rise 4 to 8 hours after the infarction and returns to normal concentration after about 10 days, being able to indicate to the doctor when the exam happened. Despite being the main marker of infarction, troponin is usually measured together with other markers, such as CK-MB and myoglobin, whose concentration in the blood begins to increase 1 hour after the infarction. Learn more about myoglobin testing.
The troponin test can also be ordered due to other causes of heart damage, such as in cases of angina that get worse over time, but that do not show symptoms of infarction.
What the result means
The result of the troponin test in healthy people is negative, as the amount of proteins released into the blood is very low, with little or no detection. Thus, if the result is negative 12 to 18 hours after heart pain, it is very unlikely that a heart attack has occurred, and other causes, such as excessive gas or digestive problems, are more likely.
When the result is positive, it means that there is some injury or change in cardiac functioning. Very high values are usually a sign of a heart attack, but lower values can indicate other problems such as:
- Very fast heartbeat; High blood pressure in the lungs; Lung embolism; Congestive heart failure; Inflammation of the heart muscle; Trauma caused by traffic accidents; Chronic kidney disease.
Normally, the values of troponins in the blood are altered for about 10 days, and can be evaluated over time to ensure that the lesion is being treated correctly.
See what tests you can do to assess your heart health.
