From the Guidelines
Right dominance in cardiac anatomy refers to the pattern of coronary arteries where the posterior descending artery (PDA) and posterior left ventricular branch (PLA) arise from the right coronary artery (RCA).
Key Characteristics of Right Dominance
- The PDA and PLA receive blood supply from the RCA 1
- This pattern is one of three mutually exclusive categories of coronary artery dominance, including right, left, and co-dominant 1
- In right-dominant circulations, the distal continuation of the RCA in the posterior atrioventricular groove gives off branches such as the posterolateral segmental artery and right posterolateral branches 1
Clinical Significance
- Determining coronary artery dominance is important in cardiac imaging and interventional procedures 1
- Coronary CTA and MRA reports should comment on the origin and course of epicardial vessels, including whether the coronary artery system is right or left dominant 1
- Accurate identification of coronary artery dominance can help guide treatment decisions and surgical planning 1
From the Research
Definition of Right Dominance
- Right dominance in cardiac anatomy refers to the pattern of blood supply to the heart, where the right coronary artery (RCA) is the dominant artery, supplying blood to the right ventricle and a significant portion of the left ventricle 2, 3.
- In right dominant hearts, the RCA gives off the posterior descending artery (PDA) and often supplies the posterior and inferior walls of the left ventricle 2.
Prevalence of Right Dominance
- Studies have shown that right dominance is present in approximately 90% of the population 3, 4.
- A study of 200 human hearts found that 178 (89%) had right dominance, characterized by the RCA giving off the PDA 2.
- Another study of 6382 patients undergoing coronary computed tomographic angiography found that 91% had right dominance 4.
Clinical Significance of Right Dominance
- Right dominance can have important implications for cardiac procedures such as angioplasty and bypass surgery 2.
- A study found that patients with right dominance and obstructive coronary artery disease had similar outcomes to those with left dominance 4.
- However, another study found that left or codominant coronary artery circulation was associated with higher in-hospital mortality among patients undergoing percutaneous coronary intervention for acute coronary syndromes 5.
- The terminal branching pattern of the RCA in left-dominant hearts has been studied, and it was found that the RCA is an inconstant and unreliable source of posterior right ventricular perfusion in a significant percentage of the population with left-coronary-dominant hearts 6.