The heart is a double pump which consists of 4 chambers which pumps oxygenated blood throughout the whole body and receives de-oxygenated blood on its return. The unique heart muscle (myocardium) is responsible for the pumping action causing the blood to flow. Like any muscle, the heart needs a good supply of oxygen and other nutrients and has its own external blood supply via the coronary arteries leading from the aorta.

Coronary artery disease is where these specific arteries become narrowed or blocked by a slow degenerative disease known as ATHEROSCLEROSIS. Fatty plaques known as ATHEROMA gradually build up on the inside of the artery walls narrowing the blood flow available to the heart muscle known as ISCHAEMIA. Sometimes the arteries become totally blocked (occluded).

This process can cause both ANGINA and in severe cases, HEART ATTACK (also known as myocardial infarction).