Two-dimensional echocardiograms of atrioventricular canal defect

Two-dimensional, four-chamber view of (A) balanced and (B) unbalanced complete atrioventricular (AV) canal defect.
(A) Balanced AV canal defect with large atrial (*) and ventricular (**) components separated by common atrioventricular valve (arrow).
(B) Unbalanced AV canal defect with right ventricular dominance, and hypoplastic left atrium and left ventricle.