Two-dimensional echocardiographic findings in double-chambered right ventricle

Rapid progression of midventricular obstruction in adults with double-chambered right ventricle

OBJECTIVE

The purpose of this study was to determine the rate of progression of midventricular obstruction in adolescents and adults with double-chambered right ventricle.

METHODS

Clinical and echocardiographic findings in 45 patients (mean age 26 +/- 6 years, range 15-44) diagnosed with double-chambered right ventricle were retrospectively analyzed. Twenty patients underwent surgical repair before the age of 15 years. The relationship between Doppler midventricular pressure gradient and patient age was analyzed in 25 patients without previous repair. Sequential change in midventricular obstruction was determined for patients with 2 or more Doppler echocardiographic examinations performed within at least a 2-year interval.

RESULTS

Right midventricular pressure gradient in nonrepaired patients was 70 +/- 38 mm Hg (range 25-150). A significant relationship between midventricular obstruction and patient age (r = 0.64, P <.001) was found. Midventricular pressure gradient at initial evaluation was 32 +/- 27 mm Hg in 16 patients < 25 years and 73 +/- 45 mm Hg in 9 patients >/= 25 years (P <.03). After the initial study, 5 patients underwent surgical repair and 13 patients without repair were followed up for a period of 6.1 +/- 2.7 years (range 2-9), in which midventricular pressure gradient increased from 32 +/- 26 mm Hg to 67 +/- 35 mm Hg (P <.001). The slope of the change in midventricular pressure gradient was 6.2 +/- 3 mm Hg per year of follow-up. Seven more patients underwent surgical repair during follow-up due to progression of the obstruction. There was no mortality nor residual midventricular obstruction in surgically repaired patients.

CONCLUSIONS

Mild right midventricular obstruction shows a fast rate of progression in adolescents and young adults. Thus, close clinical and echocardiographic follow-up is advised, and surgical repair should be considered if significant progression of obstruction is detected.

Double-chambered right ventricle: echocardiographic features

Double-chambered right ventricle is an uncommon congenital heart disease, studied mostly by angiography, characterized by the division of the right ventricular cavity into two different pressure chambers. To analyze the anatomic features of this disease, data from 13 patients examined by echocardiography at the Mayo Clinic were reviewed. Despite the anatomic variety of this abnormality, two main types were identified. In the first type, intraventricular obstruction was due to an anomalous muscle bundle crossing the right ventricular cavity from the interventricular septum to the parietal wall. In the second type, no anomalous bundles were identified, and interventricular obstruction was due to marked parietal and septal hypertrophy. The main interventricular gradient was higher in the first type, and a ventricular septal defect was found to be associated more commonly with the second type.

Transatrial repair of double-chambered right ventricle

Double-chambered right ventricles (DCRVCs) traditionally have been repaired via a right ventriculotomy. We describe the cases of 8 children (aged 7 months to 6 years; weight, 6.3 to 21.5 kg), who underwent repair of DCRV via a right atriotomy. Six patients had ventricular septal defects. Peak systolic gradients in the right ventricular outflow tract were 26 to 135 mm Hg. The QP/QS were 1.1 to 2.5. Cardiopulmonary bypass times were 52 to 89 min (mean, 65.5 min) with aortic cross-clamp times of 20 to 56 min (mean, 39 min). Mean intraoperative gradients following repair were 5.8 mm Hg. Three patients had transient postoperative atrioventricular block requiring temporary pacing. Two patients required minimal inotropic support (dopamine, 2.5 to 5 micrograms/kg/min). The children have all been asymptomatic after hospitalization with follow-up times of 5 months to 4.5 years. No patient requires cardiac medications or has significant, persistent dysrhythmias; however, 1 patient required reoperation. Transatrial repair of DCRV allows excellent operative anatomical visualization and should be considered as an alternative to the transventricular approach in patients with this congenital heart defect.