Clinical Definition

Myocardial infarction, commonly called a heart attack, usually occurs when a coronary artery becomes blocked. Coronary arteries form a network of blood vessels that surround the heart and nourish it with oxygen-rich blood, which is crucial for the heart muscle to function effectively.

In Our Own Words

Myocardial infarction, or heart attack, happens when blood flow that supplies oxygen to the heart muscle is blocked completely or reduced severely. This blockage stops flow of blood to the heart muscle, in the process both depriving it of oxygen and damaging your heart muscle.

A heart attack is not the same as cardiac arrest, but a heart attack can cause cardiac arrest (malfunction in the heart’s electrical system). A spasm in the coronary artery, if severe, may also cause a heart attack.