Hemitricuspid dysplasia in association with ventricular septal defect

The tricuspid valve essentially consists of a straight septal leaflet and a curved mural leaflet that includes the anterior and posterior leaflets. A plane bisecting the septal and anterior leaflets divides the chordopapillary support of the tricuspid valve into 2 groups. One group is related to the bulbar and adjacent perimembranous and sinus components of the interventricular septum. The other is related to the trabecular septum and the adjacent free wall. We report our surgical findings in 5 patients who had dysplasia of the leaflets and chordopapillary support related to the bulbar, perimembranous, and sinus portions of the interventricular septum, in conjunction with a perimembranous ventricular septal defect. Phylogenic, ontogenic, and surgical implications of this association are discussed.