An MI affects which blood vessels of the heart?

Myocardial infarction (MI), commonly known as a heart attack, primarily affects the coronary blood vessels of the heart. The coronary arteries supply oxygenated blood to the heart muscle itself. When there is a blockage or damage to these arteries, often due to the buildup of plaque or a blood clot, blood flow to a section of the heart can be severely reduced or cut off entirely. This lack of blood flow can lead to damage or death of the heart muscle, which is what constitutes an MI.

In contrast, the pulmonary arteries carry deoxygenated blood from the heart to the lungs, the aorta is the main artery that distributes oxygenated blood to the body, and veins generally return deoxygenated blood to the heart. Thus, while all these vessels are important in cardiovascular physiology, the coronary arteries are specifically critical in the context of a myocardial infarction.