Coronary arteries supply oxygen-rich blood to the heart muscle. Coronary artery disease results from atherosclerosis, a buildup of fatty deposits and plaque in the lining of a coronary artery, which narrows the artery and causes a decrease in blood flow to the heart muscle.
When a coronary artery suddenly becomes blocked and blood flow to an area of heart muscle stops, it is called a heart attack. A heart attack can permanently damage heart muscle and cause the affected area of the heart not to pump properly.