Double outlet right ventricle with l-malposition and uncommitted ventricular septal defect

A case is described which exhibited Double Outlet Right Ventricle (DORV) with l-malposition of the aorta in association with a ventricular septal defect of the noncommitted, atrioventricular canal variety. When the ventriculoarterial relationship of DORV is encountered, it is more usual to find the aorta to the right of the pulmonary artery. Review of the literature shows that examples of DORV and l-malposition have been described with subaortic, subpulmonary and doubly committed defects, but we are unaware of any previous example reported with a noncommitted defect. These findings indicate that DORV with l-malposition should be anticipated in association with the same accompanying defects as those described in DORV with d-malposition, and emphasize the necessity for adopting a segmental approach to nomenclature. They also have morphogenetic significance, suggesting that DORV with l-malposition is closely linked with the anomalies for anatomically corrected malposition and concordant (complete) l-transposition. The present case exhibited an electrocardiographic superior axis, which is probably related to the presence of the atrioventricular canal deformity. The coexistence of hypoplasia of the aortic isthmus is speculatively related to the presence of conal and valvar factors, which can be considered to have reduced aortic blood flow.