Shape of the anterior mitral valve leaflet?

• A. Triangular
• B. Quadrangular
• C. Circular
• D. Rectangular

Answer: (A)

The anterior mitral valve leaflet is described as triangular because it has a broad base along the annulus and narrows to a pointed tip toward the left ventricular apex. This base-to-tip taper creates a triangular silhouette on common imaging views, reflecting its large, more linear contour and chordae attachments that help pull the edge toward the ventricle. The other shapes don’t fit this typical outline: the leaflet doesn’t present a rounded circular form, nor does it consistently appear as a rectangular or evenly quadrangular shape on standard views. In contrast, the posterior leaflet has a more scalloped, varying contour, while the anterior leaflet’s geometry is the one that best aligns with a triangular appearance.