Figure 16  .

(A) The characteristic feature of a heart with atrioventricular septal defects is the oval shaped common atrioventricular junction (compare with fig 3B) and the anteriorly positioned aorta (Ao) as shown in this case with separate left and right valvar orifices. (B) Short axis cuts through the ventricle viewed from the apex show a common valve with five leaflets. The arrows indicate the peripheral parts between adjacent leaflets. (C) A long axis section of a specimen showing the superior bridging leaflet (SBL) with attachments to both ventricles and a corresponding echocardiographic section. LA, left atrium; LV, left ventricle; PT, pulmonary trunk, RA, right atrium; RV, right ventricle.