The circumflex branch of left coronary artery (also known as the left circumflex artery or circumflex artery) is a branch of the

left coronary artery The left coronary artery (LCA, also known as the left main coronary artery, or left main stem coronary artery) is a coronary artery that arises from the aorta above the left cusp of the aortic valve, and supplies blood to the left side of the ...

. It winds around the left side of the heart along the atrioventricular groove (coronary sulcus). It supplies the posterolateral portion of the left ventricle. In a minority of individuals, the left circumflex artery gives rise to the

posterior interventricular artery In the coronary circulation, the posterior descending artery (PDA), also called the posterior interventricular artery (PIV, PIA, or PIVA), is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with ...

, in which cases such a heart is deemed left dominant.

Anatomy

The left circumflex artery follows the left part of the

coronary sulcus The coronary sulcus (also called coronary groove, auriculoventricular groove, atrioventricular groove, AV groove) is a Sulcus (morphology), groove on the surface of the heart at the base of right auricle that separates the Atrium (heart), atria fr ...

, 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 In the coronary circulation, blood supply of the heart, the right coronary artery (RCA) is an artery originating above the right cusp of the aortic valve, at the Aortic sinus, right aortic sinus in the heart. It travels down the right coronary su ...

Branches

The circumflex artery curves to the left around the

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

within the

, giving rise to one or more left marginal arteries (also called obtuse marginal branches) 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

in 15% of all cases, which lies in the

posterior interventricular sulcus The posterior interventricular sulcus or posterior longitudinal sulcus is one of the two grooves separating the ventricles of the heart (the other being the anterior interventricular sulcus). They can be known as subsinosal interventricular groo ...

. In the other 85% of all cases the posterior interventricular artery comes out of the right coronary artery. When the left circumflex supplies the

posterior descending artery In the coronary circulation, the posterior descending artery (PDA), also called the posterior interventricular artery (PIV, PIA, or PIVA), is an artery running in the posterior interventricular sulcus to the apex of the heart where it meets with ...

in those 15% of cases, it is known as a left dominant circulation.

Distribution

The circumflex artery supplies the posterolateral

left ventricle A ventricle is one of two large chambers located toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in t ...

and the anterolateral

papillary muscle The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae and contract to prevent inversion or ...

. It also supplies the

sinoatrial nodal artery The sinoatrial nodal artery, sinoatrial nodal artery or sinoatrial artery is an artery of the heart which supplies the sinoatrial node, the natural pacemaker center of the heart. It is usually a branch of the right coronary artery. It passes betw ...

in 38% of people. It supplies 15–25% of the

in right-dominant systems. If the coronary anatomy is left-dominant, the circumflex artery supplies 40–50% of the left ventricle.

Additional images

File:Coronary arteries.svg, Coronary arteries (labeled in red text) and other major landmarks (in blue text). ''Left circumflex artery'' is labeled at right. File:Cardiac vessels.png, Cardiac vessel schematic File:Human heart with coronary arteries new.png, Human heart with coronary arteries File:Heart coronary territories.jpg, Heart coronary territories File:Heart left lateral coronaries diagram.svg, Heart left lateral coronaries diagram

References

External links

* – "Anterior view of the heart." * – "Posterior view of the heart." * – "Heart: The Left Coronary Artery and its Branches"
Image at merck.com

{{Authority control Arteries of the thorax