Historically, myocardial infarctions have been diagnosed by fulfilling 2 of the 3 following criteria:
- History of chest pain
- Abnormal electrocardiogram (ECG)
- Rise and fall of cardiac markers
The protein cardiac markers the lab tests for and monitors over a 24 hour period are troponin, CK-MB, and myoglobin. The first marker that is elevated is myoglobin. Since myoglobin is released from all muscle cells of the body when they die, it is nonspecific, but it helps to "rule out" or "fail to rule out" an MI. That means, the "chest pain" someone may be experiencing may be due to eating 10 kg of Gramma’s chilli causing acid reflux, or a potential heart attack. The next marker to be tested for is troponin which begins to rise after 2-8 hours after the onset of an MI and stays elevated for 5-10 days after. It is considered a "late marker" so it will still be positive if the patient doesn't come to the ER immediately, but can still receive effective treatment. And the final one is CK-MB and it's rise-fall pattern is in the middle of the 2 other enzymes so using the measurement of CK-MB and either of the other proteins, health care professionals can determine approximately the time someone has a heart attack.
|Isn't this the CUTEST LITTLE HEART?!?!|
It is the heart of the fetal pig my little sister dissected.