Figure 40c

Mitral valves from three patients with obstructive HCM, aged 31, 29, and 60 years (I, II, and III) and from a normal control patient without cardiovascular disease (IV), showing variation in valvular size and structure present in HCM. Valves are opened with the circumference displayed in a horizontal orientation, exposing the atrial surface, with anular margin to top and chordal attachments to bottom.
I. Large valve (area 22 cm2) in which both the anterior (A) and posterior (P) leaflets are greatly elongated and increased in area.
II. Large valve in which increased valve size (area 18cm2) is due primarily to elongation and enlargement of the anterior leaflet (A).
III. Segmental elongation and increased area confined to a scallop of posterior mitral leaflet.

(From HG Klues et al: Circulation 85:1651, 1992.)