View source for Circumflex branch of left coronary artery

{{Short description|Artery of heart}}
{{Redirect|Circumflex branch|the circumflex branch of the posterior tibial artery|Circumflex fibular artery}}
{{Use dmy dates|date=April 2017}}

{{Infobox artery
| Name        = Circumflex branch of left coronary artery
| Latin       = ramus circumflexus arteriae coronariae sinistrae
| Image       = Gray491.png
| Caption     = Base and diaphragmatic surface of heart. (Circumflex branch not visible, but would be near the [[coronary sinus]].)
| Image2      = Gray495.png
| Caption2    = Base of ventricles exposed by removal of the atria. (Circumflex branch not visible, but bifurcation of left coronary artery visible at left.)
| BranchFrom  = [[Left coronary artery]]
| BranchTo    = [[Left atrial branch]] <br/> [[left marginal artery]] <br/> posterolateral artery <br/> [[sinuatrial nodal artery]] (in some people) <br/> [[posterior interventricular artery]] (in some people)
| Vein        =
| Supplies    = Posterolateral [[left ventricle]], anterolateral [[papillary muscle]], the [[sinoatrial nodal artery]] in 38% of people.
}}
The '''circumflex branch of left coronary artery''' (also known as the '''left circumflex artery''' or '''circumflex artery'''{{Citation needed|date=January 2023}}) is a branch of the [[left coronary artery]]. It winds around the left side of the heart along the [[Atrioventricular groove|atrioventricular groove (coronary sulcus)]]. It supplies the posterolateral portion of the left ventricle.<ref name=":12">{{Citation |last=Wilson |first=Alexander |title=Anatomy, Thorax, Coronary Sinus |date=2022 |url=http://www.ncbi.nlm.nih.gov/books/NBK557566/ |work=StatPearls |place=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=32491498 |access-date=2023-01-05 |last2=Bhutta |first2=Beenish S.}}</ref>

In a minority of individuals, the left circumflex artery gives rise to the [[posterior interventricular artery]], in which cases such a heart is deemed [[Coronary circulation#Coronary artery dominance|left dominant]].<ref name=":12" />

==Anatomy==
The left circumflex artery 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 [[Congenital anomaly|anomalies]] described, for example the left circumflex having an aberrant course from the [[right coronary artery]].<ref>{{cite journal|last1=Page|first1=H. L.|last2=Engel|first2=H. J.|last3=Campbell|first3=W. B.|last4=Thomas|first4=C. S.|title=Anomalous Origin of the Left Circumflex Coronary Artery: Recognition, Angiographic Demonstration and Clinical Significance|journal=Circulation|date=1 October 1974|volume=50|issue=4|pages=768–773|doi=10.1161/01.CIR.50.4.768|pmid=4417692|doi-access=free}}</ref>

=== Branches ===
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) 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.<ref>{{cite book|author=Keith L. Moore|author2=Arthur F. Dalley|author3=Anne M.R. Agur|title=Clinically oriented anatomy|year=2010|publisher=Wolters Kluwer Health/Lippincott Williams & Wilkins|location=Philadelphia|isbn=978-0781775250|page=145|edition=6th}}</ref> When the left circumflex supplies the [[posterior descending artery]] in those 15% of cases, it is known as a left dominant circulation.

=== Distribution ===
{{Further|Coronary circulation#Coronary artery dominance}}
The circumflex artery 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 circumflex artery supplies 40–50% of the left ventricle.

==Additional images==
<gallery mode=packed>
 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
</gallery>

== References ==
{{Gray's}}
{{Reflist}}

==External links==
* {{SUNYAnatomyFigs|20|03|03}} – "Anterior view of the heart."{{dl|date=September 2023}}
* {{SUNYAnatomyFigs|20|04|01}} – "Posterior view of the heart."{{dl|date=September 2023}}
* {{SUNYAnatomyLabs|20|09|01|04}}{{dl|date=September 2023}} – "Heart: The Left Coronary Artery and its Branches"
* [http://www.merck.com/media/mmhe2/figures/fg020_2.gif Image at merck.com] {{Webarchive|url=https://web.archive.org/web/20060414151139/http://www.merck.com/media/mmhe2/figures/fg020_2.gif |date=14 April 2006 }}
* [http://www.cardiologysite.com/html/cx.html Overview and diagrams at cardiologysite.com]

{{Arteries of chest}}
{{Portal bar|Anatomy}}
{{Authority control}}

[[Category:Arteries of the thorax]]