branch_of regional_part_of Branch of circumflex coronary artery Circumflex branch of left coronary artery Distal portion of circumflex branch of left coronary artery Atrial branch of circumflex coronary artery Branch of circumflex coronary artery which runs parallel to the upper part of the atrioventricular sulcus and around the obtuse margin of the heart to supply the posterior wall of left atrium. FMA:3918 Left atrial circumflex artery fma