Conus artery

The conus artery is a small early branch off the right coronary artery (RCA) circulation.

Gross anatomy

Supply

The artery has a variable distribution, but usually supplies a region of the anterior interventricular septum and the conus of the main pulmonary artery (hence its name).

Variant anatomy

The artery may arise directly off the right coronary cusp, and this variant appears to have a significant genetic component.  The variant is present in ~50% of Americans, but 38% of Britons, 27% of Pakistanis, and only 10% of the Japanese population.

Since it supplies the interventricular septum, it may be enlarged in hypertrophic cardiomyopathy ⁴.

Related pathology

Although an acute occlusion of the tiny artery has been shown to result in S-T elevation, another more important role it serves in pathophysiology is that of a route of collateral circulation. The conus artery has been shown to collateralise with the more distal acute marginal branch in RCA stenosis/obstruction, and collateralise with the left anterior descending artery (LAD) in LAD stenosis/obstruction, providing a potentially vital collateral pathway.