The
Right coronary artery (RCA) originates from the right coronary (RC) cusp
and travels in the right atrio-ventricular (RAV) groove, between the right
atrium and the right ventricle. In its very proximal portion, the conus
and the sino-atrial (SA) node branch are given off. The right coronary artery
then gives rise to the acute marginal branch that travels along the anterior
portion of the right ventricle.
The RCA then continues to travel in the RAV groove. In 85% of cases,
the RCA is a dominant vessel and supplies the posterior descending branch
that travels in the PIV groove. The RCA then supplies one or more postero-lateral
(PLA) branches.
The dominant RCA system also supplies a branch to the right atrio-ventricular
node just as it leaves the right AV groove and the PDA branch supplies
septal perforators to the inferior portion of the septum
In the remaining 15% of the general population, the Cx is "dominant"
and supplies the branch that travels in the posterior inter-ventricular
(PIV) groove.
The acute marginal (AM) branch of the serves as the boundary
between the proximal and mid portion of the RCA. Thus, the portion of
the artery prior to the origin of the AM is known as the proximal
RCA, while the segment just beyond the AM is the mid RCA.
The segment halfway between the AM and the origin of the PDA is called
the distal RCA
Thus
in summary, the RCA travels in the right atrio-ventricular (AIV) groove
between the right atrium and right ventricle, as it wraps around to the
bottom or inferior portion of the heart. The
acute marginal coronary artery is given off in the proximal or early course
of the artery. While the distal portion of the RCA gives off the
PDA branch to the posterior inter-ventricular groove and then the PLA to
the posterior portion of the heart. The PDA also supplies septal perforators
to the inferior portion of the septum In
85% of cases, the Cx is non-dominant and the "dominant" RCA supplies the
PDA branch. In the other 15% of cases, a dominant Cx supplies the PDA
branch.