Figure 39a

Anatomic features of HCM are demonstrated in the heart of a 26-year-old man.
A. Exterior view; both right atrium (RA) and left atrium (LA) are dilated. Ao= aorta; PT= pulmonary trunk.
B. Radiograph of specimen showing asymmetric thickening of ventricular septum (VS).
C. Coronal section ; the septum is clearly thicker than left ventricular free wall (FW); an endocardial mural contact plaque (arrow) is present in the left ventricular outflow tract in apposition to the anterior mitral leaflet (AML).
D. closer view of plaque and thickened anterior leaflet.

(From WC Roberts, VJ Ferrans: Hum Pathol 6:287-342, 1975.)