A heart attack, also known as a myocardial infarction (MI), occurs when the flow of oxygen-rich blood to a section of the heart muscle is blocked. This blockage is often caused by a buildup of fat, cholesterol, and other substances (plaque) in the coronary arteries. When the blood flow is interrupted, the affected part of the heart muscle begins to die if it isn’t restored quickly. Heart attacks are usually caused by coronary artery disease (CAD), a condition where the coronary arteries become narrowed or blocked due to plaque buildup. A temporary tightening (spasm) of the muscles in the artery wall can also cause a heart attack.
