The Two-Chambered Right Ventricle

A relatively rare congenital cardiac malformation is described in nine patients and is characterized by aberrant hypertrophied muscular bands that divide the right ventricular cavity into two chambers. These hypertrophied muscular bands produce an effective stenosis and obstruct the outflow of blood from the right ventricle. An interventricular septal defect is usually seen in association with this abnormality. This cardiac malformation is anatomically distinct from the classic tetralogy of Fallot but may be mistakenly diagnosed as an acyanotic tetralogy of Fallot or an interventricular septal defect. The use of selective angiocardiography in conjunction with right-sided cardiac catheterization will establish the correct diagnosis. This congenital lesion is amenable to surgical correction, and five of the patients in this series were successfully operated upon with the aid of extracorporeal circulation. Surgery has been recommended for the remaining four patients because of the encouraging results.