Noncoronary Leaflet of the Aortic Valve, Lateral View

Description

Seen from a lateral peripheral viewpoint, the noncoronary (posterior) leaflet of the aortic valve forms a semilunar cusp whose free edge arcs superiorly toward the aortic lumen while its basal attachment sits inferiorly at the aortic annulus. The cusp lies posterior to the right and left coronary leaflets and, unlike them, lacks an adjacent coronary ostium, placing it closest to the posterior aortic wall. At the commissures, the free margin meets the neighboring cusps laterally, defining the points of coaptation and the adjacent interleaflet triangles. Orientation of the noncoronary cusp matters because its relationships guide both imaging interpretation and procedural planning. On transesophageal echocardiography and CT angiography, a noncoronary cusp abnormality can explain an eccentric aortic regurgitation jet directed toward the anterior mitral leaflet, and leaflet prolapse or restricted motion becomes easier to localize when you can anchor the posterior cusp in space. This is also the cusp most intimately related to the membranous interventricular septum and atrioventricular conduction tissue via the region of the noncoronary-right coronary commissure, a practical concern during surgical valve repair or TAVR deployment. Cardiac anatomy courses and cardiothoracic surgery texts use this view to teach cusp identification, commissural geometry, and the logic of coronary ostial placement relative to the aortic sinuses. It also fits well in echo and structural heart training materials that compare short-axis labeling with side-on mental models for reporting leaflet pathology. Anatomical accuracy verified by SciePro's Medical Advisory Board.