Cardiac marker

Medical tests that are often referred to as cardiac markers include:
 * cardiac troponin (the most sensitive and specific test for myocardial damage)
 * creatine kinase (CK, also known as phosphocreatine kinase or creatine phosphokinase)
 * Aspartate transaminase (AST, also called Glutamic Oxaloacetic Transaminase (GOT/SGOT) or aspartate aminotransferase (ASAT))
 * lactate dehydrogenase (LDH)
 * Myoglobin (Mb) has low specificify for myocardial infarction and is used less than the other markers.

Cardiac markers are substances released from heart muscle when it is damaged as a result of myocardial infarction. Depending on the marker, it can take between 2 to 24 hours for the level to increase in the blood. Additionally, determining the levels of cardiac markers in the laboratory - like many other lab measurements - takes substantial time. Cardiac markers are therefore not useful in diagnosing a myocardial infarction in the acute phase. The clinical presentation and results from an ECG are more appropriate in the acute situation.