rightdominant

Right-dominant is a term used in cardiology to describe a pattern of coronary artery dominance in which the posterior descending artery (PDA) arises from the right coronary artery (RCA). In this pattern, the RCA also commonly gives rise to the AV nodal artery, and the artery supplies the inferior portion of the interventricular septum.

Prevalence varies by population, but right-dominant circulation is observed in roughly 70% to 85% of individuals. Left-dominant patterns, where the PDA originates from the left circumflex artery (LCx), account for about 10% to 20%, with the remainder displaying a codominant circulation in which the PDA is from the RCA and posterior left ventricular branches are supplied by the LCx.

Anatomical implications of dominance influence the presentation and localization of ischemic events. In a right-dominant system, occlusion of the RCA or PDA can affect the inferior wall and the AV node, potentially altering conduction. In left-dominant hearts, the LCx provides a greater share of posterior myocardial supply, which can change infarct patterns and collateral considerations. Codominant circulation represents a mixed pattern where the PDA arises from the RCA while the LCx supplies posterior left ventricular branches.

Diagnosis is typically established during coronary angiography or CT coronary angiography, which visualize the origins of the PDA and other coronary branches. Dominance is a stable anatomical feature that can inform interpretation of ischemia, planning of interventions, and assessment of infarction risk.

See also: left-dominant circulation, co-dominant circulation, coronary artery anatomy.