CAD: coronary artery disease. CAD is a major cause of illness and death. It begins when hard cholesterol substances (plaques) are deposited within a coronary artery. These arteries arise from the aorta adjacent to the heart and supply the heart muscle with blood that is rich in oxygen. They are called the coronary arteries because they encircle the heart in the manner of a crown.

The plaques in the coronary arteries can cause a tiny clot to form which can obstruct the flow of blood to the heart muscle producing symptoms and signs of CAD that may include:

1. Chest pain (angina pectoris) from inadequate blood flow to the heart;
2. Heart attack (acute myocardial infarction), from the sudden total blockage of a coronary artery; or
3. Sudden death, due to a fatal disturbance of the heart rhythm.