Intermediate atrial branch of circumflex artery of heart

The intermediate atrial branch of the left circumflex (LCx) coronary artery refers to one of the small-to-medium caliber atrial branches that arise from the LCx as it courses through the left atrioventricular groove. These branches ascend from the LCx to supply the myocardium of the left atrium, including portions of the left atrial free wall, the interatrial septum, and, in some anatomical variants, the region surrounding the sinoatrial or atrioventricular nodes. The term "intermediate" designates a branch that arises from the mid-segment of the LCx between the proximal and distal portions typically in the vicinity of the obtuse marginal branches, distinguishing it from the more proximal atrial branches (such as the left atrial appendage artery or the sinus node artery when it arises from the LCx) and the more distal atrial branches near the crux of the heart.

The term "intermediate atrial branch of the circumflex artery" is not a standard, widely recognized designation in mainstream coronary artery nomenclature, and is only found in Terminologia Antomica 1&2