Double-chambered right ventricle: surgical experience and anatomical considerations.

Fourteen patients with double-chambered right ventricle underwent surgical treatment and repair of associated anomalies. The anomalous muscle band was isolated in 5 cases, associated with membranous ventricular septal defect in 7, with discrete sub-aortic stenosis in one and with double outlet right ventricle in one. All patients survived. The obstructing muscular band was a hypertrophic structure identifiable either with a displaced moderator band, still related to the anterior papillary muscle, or with a giant septoparietal band, inserting to the anterior free wall and occasionally present in normal hearts. According to this interpretation, referring the obstructive band to the septomarginal complex, double-chambered right ventricle should not be regarded strictly as a truncoconal malformation.