The protein muscles which are a part of cardiac and skeletal muscles are known as troponin. There are three kinds of troponin, Troponin I, Troponin T and Troponin C.
The functions of these troponin subdivisions are:
- Troponin T: Binds components of troponin with tropomysin
- Troponin I : Interferes and prevents any kind of interactive reaction of myosin with actin
- Troponin C: Holds binding sites for calcium ions to initiate the process of contraction.
Abnormal values of troponin acts as a marker of heart attack.
What Level of Troponin Indicates Heart Attack?
It is difficult to detect the level of troponin in people who are healthy. With the addition of more sensitive assays, the value might eventually change. The value of troponin in a patient suffering from heart diseases including chest pain and myocardial infarction is found out by using an assay in a clinical set up. With acceptable precision, more than 99th percentile of the healthy population is cut off using an assay. This is the abnormal value of troponin in patients with heart disease. The cut off point for cardiac troponin or troponin T or cTnT is 99th percentile and the amount is 0.01 ng/mL( the coefficient of the variance value at the 9th percentile being 0.03ng/mL) keeping in mind that there is only 1 cTnT assay that exists. The medical decision cut off limit or the reference decision limit (the 99th percentile of it) must be determined for Troponin T by each laboratory with inclusion of internal studies and specific assays used for clinical practises. For myocardial infraction, the cut off reference limit is more difficult to confirm.
The above values refer that whatever may be the cause, any kind of heart attack leads to the release of troponin. The initial assays were developed to track down, myocardial ischemia, a common factor of cardiac muscles being damaged. If there is an ischemic damage or during any myriad condition, you can notice the elevation in the level of troponin.
How is Troponin Released During a Heart Attack?
There are two pools of troponin, the small cytosolic pool and the large muscular pool. Troponins are released from both the pools during a heart attack and the amount of troponin released depends on the severity of the situation. Immediately after the heart attack, troponin is released from the cystolic pool which results in the elevation in the level of troponin in the system. Then the troponin muscles located in the cystol of cardiac muscles begin to diffuse across the sarcolemma. From the sarcolemma, the troponin spreads to the lymphatic and blood vessels in the surrounding. In this way troponin becomes detectable in blood. If the heart attack persists and there is a progress in the necrosis, troponin further is released from the muscular pool.
When Can You Measure the Rise and Fall of Troponin in the System?
With the older generation assay, the elevated levels of troponin could be measured and detected within 6 to 12 hours of the myocardial injury and a heart attack. The peak result would be received after 24 hours. As the heart attack is stabilized, troponin levels would slowly begin to decline and would die out from the blood within the next 2 weeks. With the modern day assay, the detection has become more précised. With 3 to 4 hours of the heart attack or the injury, troponin level in the blood can now be measured. This gives time to the doctors to take immediate action about the patient's condition which can turn out to be lifesaving. It is suggested to check the troponin again after 6 to 12 hours and once again after 24 hours.