A heart attack occurs when the arteries that supply blood to the heart muscle, become blocked.
Blood carries oxygen to the heart muscle.
When the blood flow is stopped or slowed down, the muscle does not receive the oxygen it needs, and pain, called angina, occurs. If the flow of blood and oxygen are stopped long enough, some of the heart muscle will die. This is a heart attack. Damage to the heart may be slight, with little impact in the ability of the heart to function. It may also effect the functioning of the valves in the heart.