Anterior leaflet (mitral valve, anatomy)

The anterior leaflet of the mitral valve is also termed the aortic or septal leaflets by some sources due to its proximity to these structures. It lies between the atrioventricular and aortic orifices. It is semicircular, thicker, stiffer and larger than the posterior leaflet.

The anterior leaflet is continuous with the fibrous skeleton of the heart via its lamina fibrosa which merges with:

• the right and left fibrous trigones
• the fibrous subaortic curtain between the trigones
• the proximal parts of the fila coronaria, fibrous bands extending from the trigones

The ventricular margin of the leaflet is roughened and receives a number of chordae tendinae from the ventricular surface. The rest of its surface is relatively smooth to facilitate the efficient passage of blood across it from both its atrial and ventricular sides. This is in contrast to the posterior leaflet where the chordae are attached both to the margin and the ventricular surface.