Right coronary artery

Acronym: RCA

Antoine Micheau

The right coronary artery (RCA) arises from the right coronary sinus of the aorta and courses within the right atrioventricular (AV) groove. Its anatomical segments and major branches are described as follow in coronrat CTA or DSA:

• Proximal segment: Originates at the right coronary sinus, often giving rise to the conus (infundibular) branch, which may arise independently in up to 30% of cases, and the sinoatrial (SA) nodal artery in most individuals. The conus branch supplies the right ventricular outflow tract, and the SA nodal artery supplies the sinoatrial node.

• Mid segment: Continues in the right AV groove, giving off right atrial branches and acute marginal branches, which supply the right ventricular free wall.

• Distal segment: At the crux of the heart, the RCA typically gives rise to the posterior descending artery (PDA) in approximately 80% of individuals (right-dominant circulation). The PDA supplies the inferior interventricular septum and part of the inferior wall of both ventricles. The RCA may also give off the atrioventricular (AV) nodal artery and posterolateral branches.

The RCA supplies the right atrium, right ventricle, inferior wall of the left ventricle, and the posterior third of the interventricular septum. There is significant anatomical variation, including the origin of the conus branch and the dominance pattern, which determines the extent of myocardial territory supplied by the RCA.

Segment number	Segment label	Segment location	Segment description
01	R1	Proximal right coronary artery	Extends from the ostium of the right coronary artery to the first of the three longest acute marginal branches.
02	R2	Mid right coronary artery	Extends from the origin of the first acute marginal branch to the origin of the third acute marginal branch.
03	R3	Distal right coronary artery	Extends from the origin of the third acute marginal to the origin of the posterior descending artery.
04	R4	Right posterior descending artery	In all but left dominant systems, this vessel runs in the posterior interventricular groove and supplies septal perforator branches. When present, it is one of the three longest branches on the inferior wall of the heart.
05	R5	Right posterolateral artery	This is the distal continuation of the right coronary artery after the origin of the posterior descending artery. It often has an inverted U shape as described by James and the AV nodal branch originates from this artery. It carries blood to the right posterior and right inferior arteries in large right dominant anatomy, to just the right inferior branch in small right dominant anatomy, and it is not present in left or balanced dominant systems.
	A1, A2, A3	Acute marginal arteries	The longest three arteries arising from the right coronary artery to supply the right ventricular wall, numbered from proximal to distal.
	RI	Right inferior artery	Arises from the fourth segment of the right coronary artery and supplies the inferior wall. In small right dominant anatomy, it is the distal most branch arising from the right coronary artery, while in large right dominant anatomy it arises proximal to the origin of the right posterior artery. When present, it is one of the three longest branches on the inferior wall of the heart.
10	RP	Right posterior artery	Distal most branch to arise from the right coronary artery, but present only in large right dominant systems. When present, it is one of the three longest branches on the inferior wall of the heart.

References

Wikidoc - Right coronary artery - https://www.wikidoc.org/index.php/Right_coronary_artery

Definition