<prompt> Cardiac dominance is determined by coronary aery:Supplying circulation to the SA nodeSupplying circulation to the inferior poion of the interventricular septumSupplying circulation to the interatrial septumSupplying circulation to the anterior poion of the interventricular septum  <response>: In 85 of patients the right coronary aery RCA is said to be dominant because it supplies circulation to the inferior poion of the interventricular septum the right posterior descending coronary aeryposterior interventricular aery.In these cases the RCA travels to the cross-section of the AV groove and the posterior interventricular IV groove. Here, it gives rise to the right posterior descending coronary aery PDA branch which travels in the posterior IV groove and gives off several septal perforator branches SP. The SP supply blood to the lower poion of the IV septum. Generally, the dominant RCA also gives rise to the AV nodal branch which supplies blood to the AV nodeThe dominant RCA also provides the right postero-lateral PLA branch to the lower postero-lateral poion of the left ventricle.The sinus or sino-atrial SA node branch originates in the proximal poion of the RCA in 60 of cases and as a left atrial branch of the Cx in the remaining 40 of cases. This is unrelated to whether the aery is dominant or not. 