atrial branches of coronary arteries atrial branches of coronary arteries the atrial branches of right coronary artery derive from the right coronary artery and provide part of the blood supply to the right atrium and left atrium. atrial branches of coronary arteriessternocostal surface of heart.arteries:rca = right coronaryab = atrial branchessanb = sinuatrial nodalrma = right marginallca = left coronarycb = circumflex branchlad/aib = anterior interventricularlma = left marginalpia/pda = posterior descendingmarg = left marginalavn = atrioventricular nodalveins:scv = small cardiacacv = anterior cardiacaiv/gcv = great cardiacmcv = middle cardiaccs = coronary sinusdetailssourceright coronary arteryidentifierslatinrami atriales arteriae coronariae dextraeta98a12.2.03.105 a12.2.03.214ta24134, 4149fma71668anatomical terminology although named for the right coronary artery in terminologia anatomica, a portion of the blood supply to the atria derives from the circumflex branch of left coronary artery.