Commissural Leaflets of the Mitral Valve Transverse View

Description

Cut through the heart in a transverse section, the mitral valve (valva atrioventricularis sinistra) sits between the left atrium superiorly and the left ventricle inferiorly, with the anterior (aortic) and posterior (mural) leaflets meeting at the anterolateral and posteromedial commissures. At each commissural region, the leaflet tissue narrows and blends into the chordae tendineae, which descend into the left ventricular cavity toward the anterolateral and posteromedial papillary muscles. Medially, the mitral annulus lies close to the fibrous trigones, while anteriorly the leaflet continuity approaches the aortic root via the aortomitral curtain. A tight piece of anatomy. These commissural leaflets matter because commissural pathology drives distinct regurgitant jets and repair strategies. Commissural prolapse or flail segments, often from chordal rupture in myxomatous degeneration, can be missed if you only think in terms of the broad anterior and posterior scallops, yet they change the choice between edge-to-edge repair, targeted commissuroplasty, or annuloplasty ring sizing. The transverse cut also helps correlate anatomic commissures with transesophageal echocardiography short-axis views, where identifying anterolateral versus posteromedial orientation guides localization of lesions and predicts papillary muscle involvement after ischemic injury. Use this artwork for cardiothoracic surgery teaching on mitral valve repair, for cardiology curricula linking gross anatomy to TEE interpretation, or for publishing figures on degenerative mitral regurgitation, endocarditis-related leaflet perforation near a commissure, and functional regurgitation tied to papillary muscle displacement. It also fits pathology and anatomy lab manuals that require clear labeling of commissures, annulus, chordae, and papillary muscles in section. Anatomical accuracy verified by SciePro's Medical Advisory Board.