Which coronary is dominant ?
Dominance of coronary system is defined by the origin of posterior descending artery (PDA) through which septal perforators supply the inferior one third of ventricular septum.
Right dominant coronary circulation -
When PDA originates from right coronary artery (RCA) it is called right dominant coronary circulation. It occurs in 85-90 % patients.
Left dominant coronary circulation -
When Left circumflex artery gives rise to PDA it is called left dominant circulation.It occurs in 10-15% patients.
Co-dominant circulation -
Contribution from both LCX and RCA can occur and is defined as when septal perforators from both vessels arise and supply the posterior-inferior aspect of the left ventricle.
Super-dominant circulation -
Absent left circumflex coronary artery with superdominant right coronary artery is a very rare anomaly wherein the left main coronary artery continues as left anterior descending artery. There is complete absence of the left circumflex artery and obtuse marginal artery.
The RCA is superdominant with its distal branches coursing retrogradely in the left atrioventricular groove (in the course of the normal left circumflex artery) and supplying the left ventricle. In this case, the right posterior descending artery is prominent continuing retrogradely in the left atrioventricular groove.