What does myocardial infarction directly result from?

Myocardial infarction, commonly known as a heart attack, primarily occurs due to a blockage of the coronary arteries. These arteries supply blood to the heart muscle; when they become obstructed, usually by a blood clot that forms on a ruptured atherosclerotic plaque, the flow of oxygen-rich blood to a portion of the heart is significantly reduced or completely cut off. This lack of blood flow leads to ischemia (insufficient blood supply) and subsequently results in damage to the heart tissue if not resolved quickly.

When the heart muscle is deprived of oxygen for a sufficient amount of time, the affected tissue can begin to die, leading to the clinical manifestation of a myocardial infarction. While inflammation of heart tissue can occur after an infarction as part of the healing process, it is not the primary cause of the event. Similarly, arrhythmias may be a consequence of a myocardial infarction, as the heart's electrical system can be affected by damage to heart tissue, but they don't directly cause the infarction itself. Fluid overload in the heart is associated with other conditions, such as heart failure, and does not directly lead to a myocardial infarction. Thus, the blockage of the coronary arteries is the clear and direct cause of this