Partial AV canal (equals to the ostium primum defect): an opening in the lower part of the atrial septum, right and left ventriculare orifices remain separate. There is a cleft in the anterior leaflet of the mitral valve, which causes mitral regurgitation.
Complete AV canal: the blood from all four chambers of the heart is mixed in the large defect in the lower part of the atrial septum and upper part of the interventricular septum. There is a single atrioventricular valve with five leaflets. Abnormal anterior and posterior leaflets of the common valve bridge the septal defect.
Symptomes of heart failure occur during the first months of life and half of the nontreated pacients die within six months.
Complete defect of AV septum, 22-week fetus, atrial part of the defect, view from the right atrium: AV canal, Macro, autopsy (72437)
Incomplete defect of AV septum in adult male, 50 years old, without clinical symptoms: Incomplete defect of the AV septum, Macro, autopsy (73993) Incomplete defect of the AV septum, Macro, autopsy (73994) Incomplete defect of the AV septum, Macro, autopsy (73995)