What part of the heart does the Right Coronary Artery (RCA) supply?

Right Coronary Artery Supply to the Heart

The Right Coronary Artery (RCA) primarily supplies the right atrium, right ventricle, sinoatrial node, posterior portion of the interventricular septum, and the inferior wall of the left ventricle in right-dominant circulation patterns. In most individuals (approximately 90% of people), the RCA supplies the posterior descending artery (PDA) and posterolateral branches, which provide blood to the inferior wall of the left ventricle. 1

Anatomical Distribution of RCA Supply

Major Branches and Territories

• The RCA gives rise to the posterior descending artery (PDA), which runs in the posterior interventricular groove and supplies septal perforator branches 1
• The posterolateral segmental artery represents the distal continuation of the RCA in the posterior atrioventricular groove after the origin of the PDA in right-dominant hearts 1
• Right ventricular branches arise from the RCA to supply the right ventricular wall 1
• The RCA commonly provides the blood supply to the sinoatrial node in approximately 60% of hearts 2

Coronary Dominance Patterns

• In right-dominant circulation (most common pattern, ~90%): The PDA and posterolateral arteries (PLA) arise from the RCA 1
• In left-dominant circulation: The PDA and PLA arise from the left circumflex artery 1
• In co-dominant circulation: The RCA supplies the PDA, while the circumflex artery supplies the PLA 1

Clinical Significance of RCA Supply

Anatomical Variations

• The RCA may give off a posterior right diagonal artery (PRDA) in approximately 17% of hearts, which serves as a bridge between the RCA and left anterior descending artery 2
• In about one-third of cases, a vessel arising before the crux of the heart contributes to the supply of the left ventricle 3
• In "real right dominant" hearts (approximately 10% of right-dominant patterns), the RCA supplies the right ventricle and almost half of the left ventricle through a large posterior interventricular artery and a large extension beyond the crux 4

Pathophysiological Implications

• RCA disease can lead to right ventricular dysfunction in over 90% of cases, either alone or associated with left ventricular impairment 5
• Proximal lesions of the RCA in right-dominant hearts can cause extensive posterolateral ischemia and mitral dysfunction 4
• The most common sites for coronary artery aneurysms include the proximal RCA, along with the proximal left anterior descending artery 1

Imaging Considerations

• Multiple imaging planes and transducer positions are required for optimal visualization of all RCA segments 1
• The RCA can be visualized in several echocardiographic views, including precordial short axis at the level of the aortic valve, precordial long axis, subcostal coronal projection, and apical 4-chamber views 1
• Measurements of the RCA should be made from inner edge to inner edge, excluding points of branching which may have normal focal dilation 1

Understanding the RCA's anatomical distribution is crucial for accurate interpretation of coronary angiography, planning surgical revascularization, and evaluating the potential impact of coronary artery disease on cardiac function.