Coronary artery dominance

Coronary artery dominance refers to the coronary artery that supplies the posterior descending artery (PDA) and, by extension, the majority of the myocardium's posterior and inferior aspects. This concept is crucial in understanding the coronary circulation, which is vital for the heart's function. The determination of coronary dominance is based on which coronary artery gives rise to the PDA: the right coronary artery (RCA) or the left circumflex artery (LCx).

Anatomy and Physiology

The heart's blood supply is primarily provided by two main coronary arteries: the left and right coronary arteries, which originate from the ascending aorta just above the aortic valve. The left coronary artery quickly bifurcates into the left anterior descending artery (LAD) and the LCx. The RCA typically supplies the right atrium, right ventricle, part of the left ventricle, the sinoatrial node (in about 60% of people), and the atrioventricular node (in about 90% of people).

Coronary Artery Dominance

Coronary artery dominance is determined by the artery that supplies the PDA. In the majority of individuals (about 70-80%), the RCA is dominant, meaning it gives rise to the PDA. In about 10-20% of individuals, the LCx is dominant and supplies the PDA. In the remaining cases, there is a balanced type of dominance, where both the RCA and LCx supply the posterior interventricular septum.

Clinical Significance

Understanding coronary artery dominance is important in the context of coronary artery disease (CAD) and cardiac surgeries. The dominance pattern can influence the presentation and treatment of CAD. For instance, in the case of RCA dominance, a blockage in the RCA can significantly affect the heart's posterior and inferior parts, potentially leading to more severe outcomes.

Diagnosis

Coronary artery dominance can be determined through imaging techniques such as coronary angiography, computed tomography angiography (CTA), and magnetic resonance angiography (MRA). These methods allow for the visualization of the coronary artery anatomy and the identification of the dominant artery.

Treatment and Management

The treatment of conditions related to coronary artery dominance follows the general principles of managing CAD. This includes lifestyle modifications, pharmacotherapy, and potentially revascularization procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The specific approach depends on the severity and location of the artery blockage, as well as the patient's overall health status.

See Also

• Coronary artery disease
• Coronary circulation
• Percutaneous coronary intervention
• Coronary artery bypass grafting