Influence of procedural differences on diastolic mitral valve configuration. (a) In patients with functional MR, subvalvular tethering reduces the leaflet mobility even during diastole, because of restriction of the anterior leaflet excursion. (b) In the restrictive mitral annuloplasty (RMAP) procedure, posterior leaflet tethering is augmented by the anterior displacement of the posterior mitral annulus, with persistent restriction of the anterior leaflet excursion. This persistent restriction of the anterior leaflet excursion and augmented posterior leaflet tethering diminishes the mitral inflow angle (MIA), changing the inflow direction posteriorly. (c) An additional posterior papillary muscle relocation (PMR) procedure (red arrow) not only relocates the papillary muscles, but also pushes down the posterior mitral annulus towards the apex (pink arrow). This induces a mitral annular tilt effect, which involves augmentation of posterior leaflet tethering, diminution of anterior leaflet excursion, decreased leaflet tip opening distance, and comprehensively a severe reduction in MIA, leading to severe impairment of diastolic mitral inflow. (d) An additional anterior PMR procedure (red arrow) works not only to compensate for the posterior leaflet tethering induced by RMAP, but also to improve the restricted diastolic excursion of the anterior leaflet. Although the relocation suture may limit the maximal excursion of the anterior leaflet, MIA is well preserved and the diastolic mitral valve configuration is most physiologically maintained among these 3 surgical procedures. Mitral inflow angle (MIA): the angle between the mitral annular plane and the bisector of the anterior and posterior leaflets; Ao: aorta; LV: left ventricle; LA: left atrium.