Circumflex branch of left coronary artery

"Circumflex branch" redirects here. For the circumflex branch of the posterior tibial artery, see Circumflex fibular artery.

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

Course

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.

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 (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. 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.

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  Cardiac vessels

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  Human heart with coronary arteries

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  Heart coronary territories

• Heart left lateral coronaries diagram.svg

  Heart left lateral coronaries diagram

References

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

External links

• Anatomy figure: 20:03-03 at Human Anatomy Online, SUNY Downstate Medical Center - "Anterior view of the heart."
• Anatomy figure: 20:04-01 at Human Anatomy Online, SUNY Downstate Medical Center - "Posterior view of the heart."
• Anatomy photo:20:09-0104 at the SUNY Downstate Medical Center - "Heart: The Left Coronary Artery and its Branches"
• -442892231 at GPnotebook
• Image at merck.com
• Overview and diagrams at cardiologysite.com