Learn about CAD

The Coronary Arteries Feed the Heart

The heart is a muscular pump that supplies oxygen and nutrients to the rest of the body. Much like other organ systems, the heart also needs oxygen and nutrients. The heart pumps blood to itself through the coronary arteries. There are 5 principal coronary arteries, also called the epicardial coronary arteries because they run along the surface of the heart. These are the left main coronary artery, the left anterior descending coronary artery, the right coronary artery, the left circumflex coronary artery, and the posterior descending coronary artery. These vessels also give rise to a number of other important branches that feed the heart. In addition, there are a variety of normal anatomic variations of the coronary arterial tree. Since coronary arteries are normally fairly small vessels that move with every heartbeat, there were until recently relatively few methods to image ( take pictures of ) them non-invasively.

The Development of Coronary Artery Disease

The primary condition affecting the coronary arteries is atherosclerosis, often referred to as coronary artery disease. CAD occurs when the coronary arteries, supplying blood to the muscle of the heart, become narrowed or hardened. In medical terms, this narrowing is often referred to as stenosis. Coronary artery narrowing, or stenosis, is caused by atherosclerotic plaque deposited within the coronary artery blood vessel wall. Therefore, coronary artery stenoses are the result of narrowing of the coronary artery lumen by atherosclerotic plaque.

If a coronary artery stenosis becomes severe enough, it can restrict blood flow to the heart. If the formation of atherosclerotic plaque slowly narrows a coronary artery over a long period of time, the patient may develop chest pain or similar symptoms when the heart has its highest need for oxygen - during exercise. Chest pain resulting from coronary artery disease is referred to as angina. Angina may occur with exercise, and usually resolves with cessation of exercise. In cases of severe stenosis, angina may also occur at rest. Exercise-induced angina often becomes apparent when atherosclerotic plaque narrows the coronary artery by about 70%, whereas angina at rest becomes evident when atherosclerosis reduces the coronary artery cross-sectional area by about 90%. As a result, CAD is a relatively advanced disease by the time clinical symptoms become apparent.

Our goal as physicians is to not only detect atherosclerosis in patients with symptoms, but to find ways to detect atherosclerosis before it becomes symptomatic and institute measures to prevent its development or halt its progression.