Parietal cusp

The parietal cusp of left atrioventricular valve [Bicsupid valve; Mitral valve] is the the leaflet closer to the LV free wall, and positioned more caudodorsally. It is sometimes called the posterior, caudal, parietal, or mural leaflet. The posterior mitral leaflet has a wider mural circumference and includes some incomplete scallops, which are especially prominent in horses.

Note that the two mitral leaflets (cusps of left atrioventricular valve) are identified by an inconsistent nomenclature:

• The septal cusp is also called the anterior, cranial, or septal leaflet.

• The parietal cusp, the leaflet closer to the LV free wall, and positioned more caudodorsally, is called the posterior, caudal, parietal, or mural leaflet.

• Regardless of veterinary nomenclature, clinicians (especially echocardiographers) most often use the human terminology of “anterior” and “posterior” for these mitral components.