The Mitral Valve

The mitral valve is so named due to its appearance that resembles a bishops’ miter. Transesophageal echocardiography and the mitral valve (that sits only 5–10 cm from the transducer with nothing but blood between them) were made for each other with the spatial and temporal resolution of the technique allowing the valve with its complex structure and motion to be perfectly described. Assessment of the mitral valve (MV) is, therefore, one of the commonest indications for TEE and should be undertaken in all patients being evaluated for (preoperatively) or undergoing (perioperatively) MV surgery. The MV is one of the atrio-ventricular valves (the tricuspid valve being the other one) and has an anterior and a posterior leaflet. The posterior leaflet has clefts that divide it into 3 scallops (P1, P2, and P3); the anterior leaflet has no such scallops, but is described as having three regions that reflect those of the posterior leaflet (A1, A2, and A3 respectively). In addition to the points of apposition along the leaflets, there are anterior (adjacent to A1/P1) and posterior (adjacent to A3/P3) commissures. The nonleaflet apparatus consists of the saddle-shaped mitral annulus, the chordae tendinae (primary chordae attached to the free edges of the leaflets, secondary and tertiary chordae attached to body of leaflets), and papillary muscles (anterior: chordae attached to lateral aspects of leaflets; posterior: chordae attached to medial aspects of leaflets).