Origin of Both Great Vessels from the Right Ventricle

Abstract

Clinical, hemodynamic, and pathologico-anatomic findings were studied in 8 cases in which both great vessels took origin from the right ventricle in the absence of pulmonary stenosis. In each case, a ventricular septal defect constituted the only outlet for the left ventricle. The aortic and pulmonary valves were in approximately the same cross-sectional and coronal body planes, which contrasts to the situation in the usual ventricular septal defect, in which the aortic valve lies in a normal position, being caudal to the pulmonary valve. The clinical features simulated those of a large ventricular septal defect associated with pulmonary hypertension. The importance of distinguishing these two anomalies is emphasized, since the surgical methods for repair are different. The following findings aid in the differential diagnosis (1) ecg shows a manifest mean electric axis above the zero line, with the frontal-plane vectorial loop of the QRS directed in a counterclockwise direction and its main portion lying above the zero line; (2) cardiac catheterization or angiocardiography, or both, demonstrate that the aortic valve lies at the same cross-sectional body level as the pulmonary valve in the anteroposterior view and at the same coronal plane in the lateral view; (3) in some cases, the oxygen saturation of blood in the pulmonary artery approaches or equals that in the aorta, indicating that relatively complete mixing of pulmonary venous and systemic venous blood has occurred in the outflow tract of the right ventricle.