Double-chambered Right Ventricle: Surgical Experience and Anatomical Considerations

Abstract

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.

Initial clinical manifestations and mid- and long-term results after surgical repair of double-chambered right ventricle in children and adults

“…Some have described a hypertrophied moderator band, taking origin at an anomalous high point on the septal surface of the right ventricle 4 , 5 . Others have described them as hypertrophied accessory septoparietal bands, 6 or anomalous muscle bundles arising from the supraventricular crest and extending to the anterior wall of the right ventricle, close to the base of the anterior papillary muscle of the tricuspid valve 7 . Alva and colleagues, 8 however, offered a more precise definition of the site of the obstruction, which was within the apical trabecular component of the right ventricle, distinguishing this variant from the infundibular obstruction seen in entities such as tetralogy of Fallot.…”

The nature of the obstructive muscular bundles in double-chambered right ventricle

“…Different mechanisms have been proposed to explain the origin and nature of the obstruction. 3,11,12 Most recently, Wong and colleagues 13 suggested that the degree of superior displacement of the moderator band may help to identify those infants at risk for the development of subpulmonary obstruction. The problem with this suggestion, however, is agreeing on the nature and location of the moderator band and whether this structure truly forms the obstructing lesion.…”

“…The entity is usually accompanied by a ventricular septal defect, but other widely described associations include discrete subaortic stenosis, 14 valvular pulmonary stenosis, 15 Ebstein's malformation, tetralogy of Fallot, 9 and double-outlet right ventricle. 11 It is the relationship with tetralogy of Fallot that is of particular significance, because the subpulmonary infundibulum itself is often sequestrated in tetralogy as a discrete smooth-walled chamber distal to the constriction between the muscular outlet septum and the hypertrophied septoparietal trabeculations. This infundibular stenosis, however, can coexist in a small proportion of patients with further muscular obstruction within the apical trabecular component of the right ventricle.…”

Ruptured Valsalva Sinus Aneurysm with Ventricular Septal Defect and Double-Chambered Right Ventricle without Heart Failure: A Case Report

“…Thus, surgical treatment is necessary. While the surgical outcome in children is reported to be good [Gallucci 1980], that in adults is unclear. Although betablockers have been reported to be useful for treatment [Arai 2001], the only established therapy is the surgical removal of anomalous muscle bundles.…”