cardiovascular disorders
Overview of Coronary Artery Disease
Coronary Artery Anatomy
The right and left coronary arteries arise from the right and left coronary sinuses in the root of the aorta just above the aortic valve orifice (see figure Arteries of the heart ). The coronary arteries divide into large and medium-sized arteries that run along the heart’s surface (epicardial coronary arteries) and subsequently send smaller arterioles into the myocardium. The left coronary artery begins as the left main artery and quickly divides into the left anterior descending (LAD), circumflex, and sometimes an intermediate artery (ramus intermedius). The LAD artery usually follows the anterior interventricular groove and, in some people, continues over the apex. This artery supplies the anterior septum (including the proximal conduction system) and the anterior free wall of the left ventricle (LV). The circumflex artery, which is usually smaller than the LAD artery, supplies the lateral LV free wall. Most people have right dominance: The right coronary artery passes along the atrioventricular (AV) groove over the right side of the heart; it supplies the sinus node (in 55%), right ventricle, and usually the AV node and inferior myocardial wall. About 10 to 15% of people have left dominance: The circumflex artery is larger and continues along the posterior AV groove to supply the posterior wall and AV node. 