Right or Left dominant coronary circulations are defined by supply of PDA (and thereby the posterior septum).  The RCA supplies the PDA in ~70% and the LCx supplies in the PDA in ~20%.  ~10% of patients have a co-dominant supply.  Around 20% of patients have a third branch of the L Main, the LIM.  When present, the LIM supplies territories usually supplied by the OM and D arteries.  The anterior 2/3 of the interventricular septum is supplied by the LAD.  The posterior 1/3 is supplied from the PDA.  The Sinoatrial nodal artery is supplied from RCA in 60% of patients and from the LCx in 40%.  The Atrioventricular branch is supplied from RCA in ~ 90-95% of patients (inc via PLVB or PDA), ~ 5% are supplied from the LCA via the LCx.

BLUE = Left coronary supply, GREEN = Right coronary supply, RED = Supplied myocardium, LMain = Left main coronary artery/ Left coronary artery, LAD = Left anterior descending artery/ Anterior interventricular branch, LCx = (Left) circumflex artery, D1, D2 etc = Diagonal Branches, OM1, OM2 etc = Obtuse marginal branches/ Left marginal arteries, RMA = Right marginal artery/ Acute marginal artery, PDA = Posterior descending artery/ Posterior (or Inferior) interventricular artery, PLVB = Posterolateral ventricular branch (or artery)/ Posterior left ventricular artery.(Represents continuation of RCA beyond the origin of PDA.), LIM = (Left) intermediate artery/ Ramus intermedius artery.  RCA = Right coronary artery