ArticlesAnatomyThoraxHeartRight coronary artery

ArticlesAnatomyThoraxHeartRight coronary artery

Right coronary artery

Author: Roberto Grujičić, MD • Reviewer: Declan Tempany, BSc (Hons)
Last reviewed: October 30, 2023
Reading time: 8 minutes

Right coronary artery (Arteria coronaria dextra)

The right coronary artery (RCA) is one of two main coronary vessels that supply the myocardium (the other being the left coronary artery). It originates from the right aortic sinus of the ascending aorta and runs in the right part of atrioventricular groove (coronary sulcus) wrapping around the right side of the heart.

The right coronary artery gives rise to several cardiac arteries/heart vessels that vascularize the majority of structures located in the right aspect of the heart. These structures usually include: the right atrium, right ventricle, the interatrial and interventricular septa, atrioventricular (AV) node and sinuatrial (SA) node.

This article will discuss the anatomy and function of the right coronary artery.

Key facts about the right coronary artery
Origin	Right aortic sinus of the ascending aorta
Branches	Anterior branches Conal branch Sinuatrial nodal branch Anterior atrial branches Anterior ventricular branches Marginal branches Right marginal (acute) artery Lateral atrial branches Inferior branches Atrioventricular branches Inferior (posterior) interventricular branch Interventricular septal branches Inferolateral branch
Supply	Right atrium, right ventricle, the diaphragmatic part of the left ventricle, interatrial and interventricular septa, atrioventricular node and sometimes sinuatrial node

Contents

Origin and course
Branches and supply
Anatomical variations
Clinical relations
1. Coronary dominance
Sources

+ Show all

Origin and course

The right coronary artery originates immediately superior to the right coronary cusp of the aortic valve. From here, it descends inferolaterally, joining the right atrioventricular groove where it continues around the right cardiac border, crossing from the anterior (sternocostal) to the inferior (diaphragmatic) surface of the heart. From the margin, it continues towards the crux of the heart (the junction of the interventricular and interatrial septa).

Around this crux, the right coronary artery can either terminate or give rise to one or two large terminal branches; the inferior interventricular artery (also commonly referred to as the posterior descending artery) and inferolateral branch. When the latter happens, the right coronary artery is considered the ‘dominant’ coronary vessel, which is the case in approximately 60-80% of the population.

Before jumping into the branches and supply of the coronary arteries, why don't you give it a shot and test your knowledge with this interactive quiz?

Branches and supply

The right coronary artery gives rise to numerous branches that supply most of the right portion of the heart. Additionally, if the right coronary artery is dominant, the supply territory extends to the structures of the inferior left side. Keep in mind that coronary vessels can vary greatly in number, location and diameter, which is why their supply should be scrutinized individually.

In most cases, the supplied structures include:

Right atrium
Right ventricle
Diaphragmatic part of the left ventricle
Interatrial and interventricular septa
Atrioventricular node
Sinuatrial node

According to the location of the origins of certain vessels, the branches of the right coronary artery can be divided into three separate groups: anterior, marginal and inferior.

Anterior branches

The conal branch is first to arise from the RCA. It runs between the base of the conus arteriosus (infundibulum) and the superior part of the right ventricle. The proximal segment of the right coronary artery also gives rise to sinuatrial nodal, anterior atrial and anterior ventricular branches that supply the sinuatrial node, as well as sternocostal aspect of the right atrium and ventricle, respectively.

Marginal branches

The arterial segment situated in the atrioventricular groove gives off the right marginal (acute) artery. This relatively large branch supplies the surface of the right cardiac margin, as well as the right anterior and inferior surfaces of the right ventricle. Similar to other segments of the artery, in this area several small lateral atrial branches may arise.

Inferior branches

Upon reaching the inferior aspect of the heart, the right coronary artery gives rise to the atrioventricular nodal branch that supplies the AV node. Furthermore, several small inferior atrial and ventricular branches arise to supply the diaphragmatic surface of the right atrium and ventricle, respectively. As it approaches the crux, the RCA may give off two or three inferior interventricular branches:

The inferior interventricular (descending) branch (also commonly referred to as the posterior descending artery (PDA)) is the largest of these branches, and descends in the inferior interventricular groove. On its course, it supplies the interventricular septum and adjacent surfaces of both ventricles. When it reaches the apex of the heart it anastomoses with the anterior interventricular branch of the left coronary artery. It is important to note however that this vessel may alternatively arise from the left coronary artery, or share a joint origin with the RCA and LCA (see notes on coronary dominance below).
In most cases, the right coronary artery terminates as it gives off another terminal branch called the right inferolateral branch. This branch continues the course of RCA in the coronary sinus supplying the diaphragmatic surface of the heart.

Learn more about the coronary arteries with our articles, videos, labeled diagrams and quizzes.

Anatomical variations

Variations of each coronary vessel are very common in the general population.

The conal branch of RCA can originate directly from the right aortic sinus when it is referred to as the third coronary or preinfundibular artery. This is a clinically significant variation since in occlusion of primary coronary arteries, this artery can be a main source of blood supply to the right side of the heart.
The sinuatrial nodal branch can originate from the right coronary artery, aortic sinus or left circumflex artery.
The atrioventricular nodal and inferior interventricular branches are related to the coronary dominance. This means that they arise from the dominant coronary artery, or even from both left and right in cases of co-dominance.

Clinical relations

Coronary dominance

The term "dominance" of either side of the coronary arterial circulation is determined by which coronary artery gives rise to the inferior (posterior) interventricular artery and supplies the diaphragmatic surface of the heart. In approximately 60-80% of cases the inferior interventricular artery arises from the right coronary artery, meaning that the majority of the population has a ‘right-dominant’ coronary arterial pattern. In about 10-20% of cases, both coronary artery vessels give rise to the inferior interventricular artery, which is the case of ‘co-dominance’. The left coronary artery is dominant in the remaining 5-10%. Coronary dominance is especially critical in cardiac surgery. Research shows that left dominance is a significant risk factor for the majority of surgical interventions which is why the vessel dominance should be determined before each procedure.
It's important to keep in mind that the term ‘dominant’ is potentially misleading since it can be interpreted as the vessel which irrigates the greater portion of the myocardium. However, it is always the left coronary artery that supplies the greater myocardial portion.

Sources

All content published on Kenhub is reviewed by medical and anatomy experts. The information we provide is grounded on academic literature and peer-reviewed research. Kenhub does not provide medical advice. You can learn more about our content creation and review standards by reading our content quality guidelines.

References:

Moore, K. L., Dalley, A. F., & Agur, A. M. R. (2014). Clinically Oriented Anatomy (7th ed.). Philadelphia, PA: Lippincott Williams & Wilkins.
Netter, F. (2019). Atlas of Human Anatomy (7th ed.). Philadelphia, PA: Saunders.
Standring, S. (2016). Gray's Anatomy (41st ed.). Edinburgh: Elsevier Churchill Livingstone.
Tubbs, R. S., Shoja, M. M., Loukas, M., & Bergman, R. A. (2016). Bergman’s comprehensive encyclopedia of human anatomic variation. Hoboken: Wiley Blackwell.
Vilallonga J. R. (2003). Anatomical variations of the coronary arteries: I. The most frequent variations. Eur J Anat, 7 Suppl. 1: 29-41.
Shahoud, J.S., Tivakaran, V.S. Cardiac Dominance. 2020. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Available from: https://www.ncbi.nlm.nih.gov/books/NBK537207/

Illustrations:

Right coronary artery (Arteria coronaria dextra) - Yousun Koh

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