Circumflex branch of left coronary artery

The "LCX", or left circumflex artery (or circumflex artery, or circumflex branch of the left coronary artery) is an artery of the heart.

Circumflex branch of left coronary artery
Base and diaphragmatic surface of heart. (Circumflex branch not visible, but would be near the coronary sinus.)
Base of ventricles exposed by removal of the atria. (Circumflex branch not visible, but bifurcation of left coronary artery visible at left.)
SourceLeft coronary artery
BranchesLeft atrial branch
left marginal artery
posterolateral artery
sinuatrial nodal artery (in some people)
posterior interventricular artery (in some people)
SuppliesPosterolateral left ventricle, anterolateral papillary muscle, the sinoatrial nodal artery in 38% of people.
LatinRamus circumflexus arteriae coronariae sinistrae
Anatomical terminology


It follows the left part of the coronary sulcus, running first to the left and then to the right, reaching nearly as far as the posterior longitudinal sulcus. There have been multiple anomalies described, for example the left circumflex having an aberrant course from the right coronary artery.[1]


The circumflex artery curves to the left around the heart within the coronary sulcus, giving rise to one or more left marginal arteries (also called obtuse marginal branches (OM)) as it curves toward the posterior surface of the heart. It helps form the posterior left ventricular branch or posterolateral artery. The circumflex artery ends at the point where it joins to form to the posterior interventricular artery in 15% of all cases, which lies in the posterior interventricular sulcus. In the other 85% of all cases the posterior interventricular artery comes out of the right coronary artery.[2] When the left circumflex supplies the posterior descending artery in those 15% of cases, it is known as a left dominant circulation.

Structures supplied

The LCX supplies the posterolateral left ventricle and the anterolateral papillary muscle.

It also supplies the sinoatrial nodal artery in 38% of people.

It supplies 15-25% of the left ventricle in right-dominant systems. If the coronary anatomy is left-dominant, the LCX supplies 40-50% of the left ventricle. (See Coronary circulation for description of dominance.)

Additional images

Coronary arteries (labeled in red text) and other major landmarks (in blue text). Left circumflex artery is labeled at right.


This article incorporates text in the public domain from page 547 of the 20th edition of Gray's Anatomy (1918)

  1. PAGE, H. L.; ENGEL, H. J.; CAMPBELL, W. B.; THOMAS, C. S. (1 October 1974). "Anomalous Origin of the Left Circumflex Coronary Artery: Recognition, Angiographic Demonstration and Clinical Significance". Circulation. 50 (4): 768–773. doi:10.1161/01.CIR.50.4.768.
  2. Keith L. Moore; Arthur F. Dalley; Anne M.R. Agur (2010). Clinically oriented anatomy (6th ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. p. 145. ISBN 9780781775250.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.