Interleaflet triangles of aortic valve

The interleaflet triangles of the aortic valve are three fibrous, triangular regions located between the basal attachments of the aortic valve leaflets. Each triangle is situated beneath the commissure where two leaflets meet, and they extend from the ventricular side of the aortic root up to the sinotubular junction. These triangles are integral to the aortic root structure, forming part of the boundary between the left ventricular outflow tract and the aortic root, and are essential for the dynamic function and geometry of the aortic valve apparatus.

Each triangle is bordered by the basal attachments of two adjacent leaflets and the corresponding segment of the aortic wall. Two of the triangles (those between the right and left coronary cusps, and between the right and non-coronary cusps) are supported by underlying ventricular muscle, while the triangle between the left and non-coronary cusps is supported by fibrous tissue contiguous with the mitral-aortic fibrous continuity.

The size and shape of these triangles are asymmetric, with the left-noncoronary triangle typically being the largest.The apical angle of each triangle is generally less than 60°, and their dimensions are clinically relevant for surgical repair and imaging.