Troponins

Troponins are proteins involved in muscle contraction. When you have a heart attack, there is a part of your heart (a muscle) which is dead. The troponins leak into your blood stream. To play things safe, and based on volumes of research, troponins and EKGs are trended over hours to ensure no damage was done and to differentiate between stable angina or MI.

Make sure you tell the patient they are NPO after midnight for their stress and echo the next day :)

When cardiac muscle suffers ischemic injury, various enzymes are released that can be detected through bloodwork. The problem is that the serum levels of these enzymes don't rise immediately, depending on the specific enzyme it can take as much as 24 hours after the ischemic event for the rise in that enzyme level to reach a diagnostic threshold.

Even when using the enzyme that is the most sensitive and has the shortest duration to a peak, Troponin I, it still takes 2-3 hours for about 80% of patients who have had an MI to show a positive Troponin I result, and generally someone can't be considered "ruled out" by troponins until at least 6 hours has passed since the onset of symptoms.

Tropinins are trended q6hr x 3. You need to see where they peak. Some physicians may want trooponins trended post PCI-you will see elevated troponins post intervention as the myocardial tissue releases troponins after PCI or defibrillation-but they should trend down and not peak.

I agree with the other posts. They're looking for the trend. Many times the injury will make the first one or second one high and then they start decreasing. We also use them if an injury is suspected (like if a pt seems like they're in the process of an MI) to help with the diagnosis. 3 times is usually enough to get a feel for where the pt is headed xo