DOUBLE CHAMBER RIGHT VENTRICLE (DCRV)

DCRV is a rare anomaly that accounts for between 0.75% and 1.5% of all cardiac defects (1).

Its main characteristic is one or more abnormal muscle bundles dividing the right ventricle into a proximal high-pressure and a distal low-pressure chamber (1,2).

The origin of this muscular bundle is not clear, with many authors suggesting a hypertrophied moderator band.

CAUSES OF NON-IMMUNE HYDROPS

Fetal cardiac causes of NIH include (3-5):

· arrhythmias such as supraventricular tachycardia

· congenital complete heart block

· structural cardiac anomalies such as:

o pulmonary atresia,

o hypoplastic left heart syndrome,

o hypoplastic right heart syndrome,

o Ebstein's anomaly

o premature closure of the foramen ovale and/or the ductus arteriosus

o Double chamber right ventricle (DCRV).

ULTRASOUND

· Diagnosis is usually made in childhood, depending on the symptoms due to the associated VSD as well as to the often progressive degree of right ventricular obstruction.

· The mean age at diagnosis ranges between 2.5 and 9.5 years (1,2,6).

· Antenatal diagnosis is exceedingly rare, with only three prenatally diagnosed cases reviewed in the literature (7-9).

o In one case, the infant survived and subsequently underwent surgery.

o The other two case describes the fetus also had an intact ventricular septum, developed fetal hydrops and died of cardiac insufficiency after delivery (8,9). Apparently, obstructing right ventricular muscle bundles in the presence of an intact ventricular septum leads to a much more profound disturbance of fetal hemodynamics.

DCRV with an intact ventricular septum at 20 weeks of gestation. Fetus developed cardiac failure at 28 weeks of gestation and died in utero

ASSOCIATED MALFORMATIONS

VSD - 63-95% of cases (7,10,11).

The prognosis following surgical correction, which is now generally performed by a transatrial approach, is excellent (8,10). with long-term disease-free survival approaching 100%.

REFERENCES

1. Cabrera A, Martinez P, Rumoroso JR, Alcibar J, Arriol J, Pastor E, Galdeano M. Double-chamber right ventricle. Eur Heart J 1995; 16: 682-686.
2. Hachiro Y, Takagi N, Koyanagi T, Morikawa M, Abe T. Repair of double-chamber right ventricle: surgical results and long-term follow-up. Ann Thorac Surg 2001; 72: 1520-1522
3. Rejjal A, Rahbeeni Z, Al-Zahrani A. Prognostic factors and prenatal management in non-immune hydrops fetalis are still a dilemma. J Perinat Med 1996; 24: 461-466.
4. Ismail KM, Martin WL, Ghosh S, Whittle MJ, Kilby MD. Etiology and outcome of hydrops fetalis. J Matern Fetal Med 2001; 10: 175-181.
5. Mielke G, Steil E, Breuer J, Goelz R. Circulatory changes following intrauterine closure of the ductus arteriosus in the human fetus and newborn. Prenat Diagn 1998; 18: 139-145.
6. Alva C, Ortegon J, Herrera F, Melendez C, David F, Jiminez S, Jiminez D, Sanchez A, Hernandez M, Ledesma M, Arguero R. Types of obstructions in double-chamber right ventricle: mid-term results. Arch Med Res 2002; 33: 261-264
7. Leandro J, Dyck JD, Smallhorn JF. Intra-utero diagnosis of anomalous right ventricular muscle bundles in association with a ventricular septal defect: a case report. Pediatr Cardiol 1994; 15: 246-248.
8. Marton T, Hajdu J, Papp Z. A rare case of non-immune hydrops fetalis: double chamber right ventricle. Fetal Diagn Ther 2001; 16: 251-253
9. S. Becker , M. Hofbeck, H. Kendziorra et.al. Double-chamber right ventricle associated with severe fetal cardiac failure. Ultrasound Obstet Gynecol 2005;23:419-421.
10. Galal O, Al-Halees Z, Soymar L, Hatle L, Mieles A, Darwish A, Fawzy ME, Al Fadley F, de Vol E, Schmaltz AA. Double-chamber right ventricle in 73 patients: spectrum of the disease and surgical results of transatrial repair. Can J Cardiol 2000; 16: 167-174.
11. Singh M, Agarwala MK, Grover A, Pathak V, Varma JS. Clinical, echocardiographic and angiographic profile of patients with double-chamber right ventricle: experience with 48 cases. Angiology 1999; 50: 223-231