Which cardiac enzyme is primarily elevated in myocardial infarction?

Troponin is the cardiac enzyme that is primarily elevated in myocardial infarction. This protein is specific to cardiac muscle and is released into the bloodstream when there is damage to heart tissue, such as during a heart attack. The elevation of troponin levels is a key marker used in the diagnosis of myocardial infarction because it provides a reliable indication of cardiac injury.

Troponin levels can start to rise within a few hours after the onset of myocardial injury and may remain elevated for several days, making it a valuable diagnostic tool for patients who may seek medical attention days after experiencing symptoms. This specificity for cardiac cells makes troponin a more definitive marker compared to other enzymes.

While other markers like creatine kinase, myoglobin, and lactate dehydrogenase can also indicate myocardial injury, they are either less specific to cardiac tissue or may not remain elevated as long as troponin, which is why troponin is considered the gold standard in diagnosing myocardial infarction.