The right coronary artery originates above the
right aortic sinus above the
aortic valve.
Segments • Proximal: starting at RCA origin, spanning half the distance to the
acute margin • Middle: from proximal segment to the acute margin • Distal: from middle segment to origination point of the posterior interventricular artery, where the
posterior interventricular sulcus meets the
atrioventricular groove on the base of the heart.
Variation In approximately 80% of patients (right dominant), the RCA gives off the
posterior descending artery (PDA). In the other 20%, of cases (left dominant or codominant), the PDA arises from the
left circumflex artery or is supplied by both the right coronary artery and the left circumflex. The PDA supplies the
inferior wall,
ventricular septum, and the posteromedial
papillary muscle. The RCA also supplies the
SA nodal artery in 60% of people. The other 40% of the time, the SA nodal artery is supplied by the
left circumflex artery. Although rare, several anomalous courses of the right coronary artery have been described including origin from the left aortic sinus.
Distribution The right coronary artery supplies oxygenated blood to the
right atrium, the
right ventricle, and the posterior third and inferior end of the
interventricular septum. There is significant
overlap of supply of the
coronary arteries. The right coronary artery is dominant over the
left coronary artery 50% of the time, equal to it 20% of the time, and less significant than it 30% of the time. ==Additional images==