title: Double-outlet right atrium with two atrioventricular valves and left atrial outlet atresia.
abstract: In double-outlet atrium either the right or the left atrium empties into both ventricles while the other atrium remains disconnected from the ventricular cavities. Cases of double-outlet atrium with a single atrioventricular (AV) valve have been reported but no cases of double-outlet left atrium and only two of double-outlet right atrium (one with three valves) have been reported. A description of the second case of double-outlet right atrium with two AV valves and a review of the other reported case are presented. Common anatomic characteristics were: two AV valves in the right atrium that connected with two normal ventricles; disconnection of the left atrium from the ventricular cavities; an atrial septal defect in a malpositioned atrial septum; and drainage of a left superior vena cava into the left atrium. Mitral incompetence was found in both cases. Clinical findings were similar to those seen in ostium primum atrial septal defect. Two-dimensional echocardiography and angiocardiography are able to accurately demonstrate this entity. Successful surgical correction was performed in both cases. Two morphogenetic hypotheses are proposed: abnormal development of the septum primum or primitive malposition of the common atrioventricular canal.
mesh_terms: D006328:Cardiac Catheterization; D002648:Child; D004452:Echocardiography; D006325:Heart Atria / Q000002:abnormalities; D006330:Heart Defects, Congenital / Q000473:pathology* / Q000601:surgery; D006344:Heart Septal Defects, Atrial / Q000473:pathology; D006351:Heart Valves / Q000002:abnormalities; D006801:Humans; D008297:Male; D014683:Vena Cava, Superior / Q000002:abnormalities