LAUSR

F unction of the mitral valve (MV) requires a complex interplay among the annulus, leaflets, and subvalvular apparatus (1). Mitral annulus is a 3-dimensional saddle-shaped structure exhibiting dynamic conformational change during the cardiac cycle. Morphologically, it is a fibrous structure conventionally divided into an anterior and posterior portion, although the real mitral annulus is along the atrioventricular junction that serves as hinge point for the mural leaflet of MV. The anterior portion is between the right and the left trigones, at the level of the so-called “mitro-aortic fibrous continuity.” As a fibrous structure, the motion of the annulus is passive and is determined by the contraction and relaxation of adjacent atrial and ventricular musculature, as well as by the motion of the aortic root (1).