Left atrial outflow obstruction in double-outlet right atrium.

We describe an unusual case of partial atrioventricular septal defect with malalignment of the septum primum to the left atrium with respect to the ventricular septum, committing the tricuspid valve to both ventricles (double-outlet right atrium). Abnormal attachment of the septum primum to the lateral aspect of mitral annulus resulted in left atrial outflow obstruction. The patient underwent successful surgical correction.