ORIGIN OF BOTH GREAT VESSELS FROM THE RIGHT VENTRICLE WITHOUT PULMONARY STENOSIS

Publisher Website
Google Scholar
Abstract
Clinical, hemodynamic, roentgenographic, and anatomical findings are presented for 10 patients with origin of both great vessels from the right ventricle without pulmonary stenosis. A new classification into 2 main types is offered, based on the anatomical position of the ventricular septal defect. The sub-group in which the ventricular septal defect lies below the crista supraventricularis is designated as Type I, that in which the defect lies above the crista supraventricularis as Type II. In each case in both types, the ventricular septal defect constituted the only outlet for the left ventricle. In all patients the aortic and pulmonary valves lay in approximately the same cross-sectional and coronal body planes. Usually, the mitral valve did not show continuity with the aortic valve. In Type I, these valves might occasionally be continuous because of an unusual long anterior leaflet on the mitral valve. The clinical features in Type I simulated those in cases of large ventricular septal defect associated with pulmonary hypertension. The electrocardiographic findings differed strikingly from Type I to Type n. In patients of Type I the mean manifest electrical axis ranged from plus 60 degrees to minus 70 degrees, the vector loop in the frontal plane being directed counterclockwise in four of the six patients. In patients of Type II the QRS axis was between plus 110 and plus 130 degrees. Electrocardiographic findings of a counterclockwise loop in the frontal plane in the presence of clinical and laboratory findings like those in ventricular septal defect with marked pulmonary hypertension should arouse the suspicion of origin of both great vessels from the right ventricle without pulmonary stenosis, Type I. Selective angiocardiography and aortography are particularly important in establishing the diagnosis. Since the surgical approach employed in this malformation differs from that followed in the usual ventricular septal defect, the importance of distinguishing these two anomalies is obvious. Patients with the Type II malformation presented a picture of cyanotic congenital heart disease associated with increased pulmonary arterial flow. The position of the defect in this type enables oxygenated blood from the left ventricle to enter directly into the pulmonary artery and is therefore responsible for the different haemodynamic and clinical findings as compared to Type I. Selective angiocardiography and haemodynamic studies are strongly recommended for establishing a clinical diagnosis of origin of both great vessels from the right ventricle without pulmonary stenosis Type II and for distinguishing Types I and II. While a curative surgical procedure is available for the Type I malformation, none has yet been established for Type II.