Diverticulum of the right ventricle associated with ventricular septal defect.

A true diverticulum of the ventricle is a very rare congenital cardiac lesion which is characterized by a normal myocardial wall and active participation in the ventricular contractions. Diverticula of the right ventricle may originate from the apical or anterosuperior wall. We report three patients with an anterosuperior diverticulum of the right ventricle associated with a perimembranous ventricular septal defect, one of whom additionally had obstruction of the right ventricular outflow tract. These patients presented clinically with symptoms related only to their associated defects. The right ventricular diverticulum was diagnosed by angiography in all, but was also seen on cross-sectional echocardiography in one patient. The ventricular septal defect was repaired through an incision of the diverticulum, which was reduced in size at the same time. Complete resection appears necessary only if severe endocardial fibrosis is present within the diverticulum, because such a diverticulum does not contribute to right ventricular contraction, but rather is at risk of rupture.