Vessel
Left coronary artery
The usual common stem of the left coronary branches
High-yield
Left main disease can threaten the combined territories of both major left coronary branches.
Overview
The left main coronary stem begins in the left aortic sinus and passes between the pulmonary trunk and left atrial appendage. It usually divides into anterior interventricular and circumflex arteries; an intermediate branch may also arise at that division.
Reference facts
- Origin
- Usually the left aortic sinus
- Course
- A short passage behind the pulmonary trunk toward the space beside the left atrial appendage
- Branches
- Anterior interventricular and circumflex arteries, sometimes with a ramus intermedius
- Supplies
- Much of the left ventricular myocardium and septum through its branches, with territorial variation
- Drains to
- Venous return from its territory passes through cardiac veins, predominantly into the coronary sinus
Clinical correlation
The consequences of left main narrowing depend on severity, flow and the myocardium supplied. Anomalous origins require assessment of the entire course; an unusual origin alone does not define its risk.
Frequently asked questions
Where does the left coronary artery originate?
Usually the left aortic sinus.
What does the left coronary artery supply?
The left coronary artery supplies the much of the left ventricular myocardium and septum through its branches, with territorial variation.
Where does the left coronary artery drain to?
The left coronary artery drains to the venous return from its territory passes through cardiac veins, predominantly into the coronary sinus.
What are the branches of the left coronary artery?
Anterior interventricular and circumflex arteries, sometimes with a ramus intermedius.