The coronary arteries arise just distal (superior) to the aortic valve from the coronary sinuses and supply the myocardium with oxygenated blood. They divide and encircle the heart to cover its surface with a lacy network resembling perhaps a slightly crooked crown.
The typical configuration consists of two coronary arteries, a left coronary and a right coronary, arising from the left and right aortic or coronary sinuses respectively, in the proximal ascending aorta. There are the only two branches of the ascending aorta.
The right coronary courses in the right atrioventricular groove to the inferior surface of the heart, whereupon it turns anteriorly at the crux as the inferior interventricular artery (in right dominant circulation).
The left coronary has a short common stem (and is hence often also known as the left main coronary artery, LMCA) before dividing into the left circumflex artery (LCx), which courses over the left atrioventricular groove, and the left anterior descending artery (LAD), which passes towards the apex in the anterior interventricular groove. Occasionally there is a trifurcation (in ~15%), with the third branch arising in between the LAD and LCX, the ramus intermedius. In left dominant hearts the left circumflex supplies the inferior interventricular artery.
- left coronary artery branches
- right coronary artery branches (RCA)
Although there are variations (see main article: congenital coronary artery anomalies), the anatomy is relatively consistent.
History and etymology
Coronary comes from the Latin "coronarius" meaning belonging to a crown or wreath.