Coronary Artery Disease
The heart is supplied consists of 3 coronary arteries: The left sided coronary artery starts as the left main stem which is usually very short in length. This then divides into 2 further arteries: the left anterior descending artery (commonly called the LAD) and the left circumflex artery. The LAD supplies the front of the heart and the majority of the left ventricle, which is the main pumping chamber of the heart. The left circumflex supplies the back of the heart. The right coronary artery starts from the right side of the heart and generally supplies the underside of the heart.
Overtime all these arteries can develop coronary atheroma: the term for narrowing of the heart arteries. This then leads to reduced blood supply to the heart especially when the heart needs to work harder than normal such as during exercise. When the heart muscle does not receive enough blood supply this causes chest pain or angina. These arteries can also suddenly block off if a clot forms within them. In this situation the chest pain will occur at rest and is what happens when a heart attack occurs.