The coronary arteries , illustrated at right, surround the heart to supply the heart muscle with the fresh blood nourishment it needs to do its work of pumping blood throughout the rest of the body. Just like other organs, the heart needs a constant supply of oxygenated blood to feed itself. When the body goes into more strenuous activity, the heart has to work harder to supply the body's demands for fresh, oxygen-rich blood. When this happens, the heart's own need for oxygen rich blood rises, and the constrictions in coronary arteries prevent it from receiving the necessary amount. The image below left is an arteriogram showing occlusion of the right coronary artery.
Stenosis is the diseased arterial tissue.
A buildup of stenosis results in occlusion, or blockage, of an artery. An ischemic heart reacts by giving off a sensation of pain. We call this pain angina , or, more technically, angina pectoris . The heart tissue supplied by that coronary artery begins to die, and some of the heart muscle may be permanently damaged, or, in very severe cases, may result in death of the patient. The earliest symptoms of CAD may be angina, shortness of breath, or both.