Many survive with few aftereffects. Others do not survive. The heart is a muscle that pumps blood throughout the body. To stay healthy, the heart needs oxygen and other nutrients that are carried by the blood. It gets these by way of the coronary arteries, which wrap around the outside of the heart.
Diseases can affect any part of the heart.
However, the most common is the insidious disease of the coronary arteries called atherosclerosis. When this occurs, plaque, or fatty deposits, develops in the artery walls. Over a period of time, plaque can build up, harden and narrow the arteries, and restrict blood flow to the heart. Clogging in one or more arteries precipitates an attack when the heart's demand for oxygen exceeds the supply. Diseased arteries are also more susceptible to spasm.