Atrial Functional Mitral Regurgitation: from Echo to the surgical view

Atrial functional mitral regurgitation (A-FMR) is characterized by atriogenic leaflet tethering, often associated with mitral annular dilatation and dysfunction caused by left atrial enlargement.1 In advanced forms with huge left atrial volumes, dislocation of posterior mitral annulus toward the outside of the myocardium (Fig. 1, A) has been recently described2; this is a rare subtype in which the stretched atrial wall displaces the posterior mitral annulus backward, onto the crest of the left ventricle.