Cardiology and Angiology: An International Journal

Double-chambered right ventricle (DCRV) is an uncommon congenital cardiac anomaly characterised by division of the right ventricle into two functionally distinct chambers by an anomalous or hypertrophied muscular bundle. Although usually diagnosed during childhood, progressive obstruction may result in symptomatic presentation during adulthood and can mimic isolated subpulmonary or pulmonary valvular stenosis. We report a 21-year-old man with progressive exertional dyspnoea who had previously undergone balloon pulmonary valvotomy for presumed isolated subpulmonary stenosis, with only partial symptomatic improvement. Subsequent evaluation demonstrated severe intraventricular obstruction due to DCRV, with an echocardiographic peak gradient of 85 mmHg. Surgical excision of the obstructing muscular bundle was recommended; however, the patient declined surgery. Following detailed counselling and shared decision-making, balloon dilatation was performed using a 24-mm Accura balloon. Three balloon inflations resulted in a reduction in right ventricular pressure from 72/5 mmHg to 45/0 mmHg, with a residual peak gradient of 38 mmHg. The patient experienced significant improvement in exercise tolerance and had an uncomplicated recovery. Cardiac magnetic resonance imaging confirmed a hypertrophied anomalous muscular band measuring 4.4 mm, dividing the right ventricle into proximal and distal chambers, with a 7.3-mm communication between them. Balloon dilatation may provide short-term symptomatic and haemodynamic improvement in carefully selected patients with DCRV who decline definitive surgical treatment. However, the underlying muscular obstruction persists, and close follow-up is necessary to monitor for recurrent or progressive obstruction.