Left coronary artery

Overview
The left coronary artery, abbreviated LCA and also known as the left main coronary artery (often abbreviated LMCA), arises from the aorta above the left cusp of the aortic valve.

Branching
It typically runs for 1 to 25 mm and then bifurcates into the anterior interventricular artery (also called left anterior descending (LAD)) artery and the left circumflex artery (LCX).

The part that is between the aorta and the bifurcation only is known as the left main artery (LM), while the term 'LCA' might refer to just the left main, or to the left main and all its eventual branches.

If an artery arises from the left main between the LAD and LCX, it is known as the ramus intermedius. The ramus intermedius occurs in 37% of the general population, and is considered a normal variant.