What is Cardiac Marker Test and when Should It Be Done?

What is cardiac markers test? Cardiac markers refer to myocardial markers that can diagnose cardiac injury including myocardial infarction and myocardial minor injury, mainly including cardiac enzymes including creatine kinase and isoenzyme, aspartate aminotransferase lactate dehydrogenase, hydroxybutyrate dehydrogenase, myoglobin, troponin, etc.

1. Need for cardiac marker test

All diseases that may cause heart damage should be frequently tested for cardiac markers list, such as coronary heart disease, hypertension, myocarditis, cardiomyopathy, cor pulmonale, cardiac insufficiency, other diseases that damage the heart muscle and taking drugs that damage the heart muscle In such cases, cardiac markers should be checked. Items that can be detected with minimal damage to the heart are myoglobin and troponin. In addition, for older people, those with cardiovascular disease risk factors such as hyperlipidemia and obesity should also frequently observe some examination items that have predictive value for coronary heart disease risk, such as high-sensitivity C-reactive protein, high-density lipoprotein to low-density lipoprotein ratio, fibrinogen.

2. Clinical significance of cardiac marker test results

(1) Creatine kinase, creatine kinase isoenzyme, aspartate aminotransferase, lactate dehydrogenase, hydroxybutyrate dehydrogenase: mainly used for the diagnosis of myocardial infarction, and also have good diagnostic significance for myocarditis less sensitive to myocardial injury.

Creatine kinase isoenzyme has high specificity for myocardial injury. Creatine kinase mm, aspartate aminotransferase, lactate dehydrogenase, and hydroxybutyrate deoxygenase are not only increased during myocardial injury, but also increased in other parts of muscle damage. High, such as muscle damage caused by intense exercise, muscle inflammation, etc. Aspartate aminotransferase and lactate dehydrogenase can also be elevated in the presence of liver inflammation, biliary tract disease, etc., especially the single elevation of lactate dehydrogenase can sometimes indicate the possibility of cancer, and further examination is required.

(2) Myoglobin and troponin: These two items are new items that have only been detected in recent years, with good specificity and sensitivity, and can be detected at an earlier time of onset, with great advantage. Myoglobin can be detected in the blood at 1.5 to 2 hours after acute myocardial infarction, and it reaches a peak at 4 to 6 hours. Therefore, the cardiac marker test is particularly suitable for early diagnosis of myocardial infarction. And because of the high sensitivity of this project, it can detect small myocardial damage, so it has good diagnostic value for myocarditis, hypertensive myocardial damage, heart failure, pulmonary heart disease myocardial damage, etc.

Troponin appears in the blood later than myoglobin after myocardial infarction, about 3 to 6 hours after chest pain, but it is the most specific item of myocardial injury, so it has a decisive diagnostic value. Like myoglobin, it has diagnostic significance for myocardial damage caused by other causes or diseases, but troponin disappears in the blood for a longer time, so it is more valuable for patients with a longer onset time, and can be used as a disease observation index.