Septal branches of anterior interventricular artery

At a glance

English

Septal branches of anterior interventricular artery

Latin (TA2)

Rami interventriculares septales rami interventricularis anterioris arteriae coronariae sinistrae

System

Heart

Region

Trunk

Side

Single, on the midline

About the septal branches of anterior interventricular artery

The septal branches are a row of small arteries given off from the deep surface of the anterior interventricular artery (the left anterior descending artery) as it runs down the anterior interventricular groove. Rather than spreading over the surface of the heart, they turn at roughly right angles and dive into the muscular interventricular septum, the thick wall that divides the left ventricle from the right. Because of this they are often called septal perforators.

Their number varies, commonly from about four up to a dozen or more. The first septal branch, which arises near the start of the anterior interventricular artery, is usually the largest and runs deep into the upper part of the septum. Later branches become progressively shorter and smaller towards the apex. Inside the septum they branch and link up with septal twigs from the posterior (inferior) interventricular artery, which enter from below and behind, so the septum has a double supply with a potential collateral route between the left and right coronary systems.

Together these vessels supply roughly the front two-thirds of the septum. That territory contains the bundle of His as it divides and the right and left bundle branches, so their blood flow matters for conduction as well as for contraction. A blocked anterior interventricular artery proximal to the first septal branch can therefore cause bundle-branch block as well as an anterior infarct.

The first septal branch has a particular use in treatment. In hypertrophic cardiomyopathy with obstruction of the left ventricular outflow, a small dose of alcohol can be injected into it through a catheter to shrink the thickened upper septum, a procedure called alcohol septal ablation.

Function and supply

Begins at

The deep surface of the anterior interventricular artery along its course in the anterior interventricular groove; the first septal branch arises close to its start.

Ends at

Branch within the muscular interventricular septum and link with septal branches of the posterior interventricular artery.

Function

Supply about the anterior two-thirds of the interventricular septum, including the bundle of His and the right and left bundle branches.