What is a heart attack?

A heart attack occurs when there is a severe blockage in an artery that carries oxygen-rich blood to the heart muscle. The blockage is usually caused by the buildup of plaque (deposits of fat-like substances, or atherosclerosis) along the walls of the arteries. The sudden lack of blood flow to the heart muscle deprives the heart of needed oxygen and nutrients. If the blockage is not opened quickly, the heart muscle is likely to suffer serious, permanent damage as areas of tissue die.

The medical term for a heart attack is acute myocardial infarction. Acute means sudden, myo refers to muscle, and cardia refers to heart. The myocardium is the medical name for the heart muscle. Infarct means that (heart) tissue has been destroyed or killed because of the clogging of the blood vessels that supply oxygen to the heart.