Coronary arteries bring blood and oxygen to nourish the heart. The heart pumps unoxygenated blood to the lungs, where it receives oxygen and nutrients. The heart then Unoxygenated Blood pumps the oxygen-rich blood to the whole body. Because the heart is a muscle, it needs a steady source of blood to be nourished.

Coronary artery disease (CAD) is caused by atherosclerosis, commonly known as hardening of the arteries. Atherosclerosis is a buildup of fatty deposits within the walls of the arteries. These deposits are called plaque. The lining of the artery becomes thickened and roughened by these fatty substances. Atherosclerotic plaque causes blood flow restrictions and blockages within the coronary arteries leading to the heart, resulting in angina (chest pain), heart attacks and other complications. As the arteries surrounding the heart continue to close, the blood supply needed by the heart muscle to function is reduced or blocked completely. As the narrowing becomes severe, a heart attack can occur.

Overview of Coronary Artery Disease