The left coronary artery (LCA) is one of the two arteries that supply oxygenated blood to the heart muscle. It arises from the left side of the initial part of the ascending aorta. Its opening is located just above the left semilunar cusp (sinus of Valsalva) of the aortic valve.

The LCA passes between the left auricle (left atrial appendage) and the pulmonary trunk. Further, it passes into the superior aspect of the atrioventricular groove, turning left toward the right border of the heart.

Within the groove, the LCA bifurcates and splits into two branches - the anterior interventricular artery and the circumflex artery. (Study these arteries in more detail on the next slide.)

Before the bifurcation, there are usually no branches arising from the left coronary artery. However, sometimes the LCA gives off a small sinoatrial node artery.

Overall, with its branches the LCA supplies the left atrium, most of the left ventricle, part of the right ventricle, and the majority of the interventricular septum, as well as the atrioventricular bundle and, in some cases, the sinoatrial node.

Unlock with Premium

Left coronary artery (LCA)