Biochemical indicators of acute myocardial infarction

Acute coronary syndromes (ACS; acute myocardial infarction, AMI, and unstable angina pectoris) are usually caused by coronary artery occlusion due to thrombotic complications. When blood flow is restricted, "myocardial ischemia" occurs, which is initially "reversible". If it is not possible to restore the blood flow in time, "irreversible" changes occur after about an hour, accompanied by the death of cells and necrosis (definitive myocardial infarction).

Laboratory investigation methods play an important role in the diagnosis of acute coronary syndrome. Biochemically important components of the cardiomyocyte are found ``in the cytoplasm or mitochondria and others are part of the ``contractile apparatus. During a myocardial infarction, they are released into circulation. The course of their serum levels is dependent on several factors:


 * on localization in the cell;
 * During ``short-term ischemia, ``cytoplasmic proteins are washed into the blood circulation as a result of functional and later also structural changes in cell membranes.
 * With "longer-term ischemia" tissue necrosis develops and "structural proteins" are also released into the bloodstream. Thus, cytosolic proteins are released faster than structural proteins.
 * on relative molecular weight – smaller proteins are released into the circulation faster;
 * on the rate of excretion – smaller molecules are eliminated faster by the kidneys;
 * on blood flow in the affected area.

Aspartate aminotransferase
Aspartate aminotransferase' (AST) is contained in the myocardium in a relatively high concentration. Historically, it was one of the first used biochemical indicators of acute myocardial infarction, but today it is no longer recommended for this indication.

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