Abstract 16827: Double-chambered Right Ventricle Diagnosed in Late Adulthood by Multi-modality Imaging. Report of Two Cases With Associated Aortopathy

Introduction: Double-chambered right ventricle (DCRV) is a rare congenital disorder. The right ventricle (RV) is divided into two: a high-pressure inlet and a low-pressure outlet by an abnormal muscle bundle. Rarely diagnosed in adulthood, it is associated with other congenital defects. Association with aortopathy is not described. Patient 1: 67 year-old male with dyspnea: PE: grade 4 harsh systolic murmur radiating to the base. Echo: DCRV with obstruction -peak gradient (PG) 75mmHg (Fig 1-C), hypertrophied/dilated RV, decreased function; small perimembranous VSD, small right-to-left shunt. Ascending aorta aneurysm: 49 mm (Fig 1-D). Normal aortic valve. MRI: DCRV with muscle bundle causing RVOT obstruction. RV with delayed gadolinium enhancement (Fig 2). Heart cath: severe RV obstruction (PG 105 mmHg). Surgery: Resection of the muscular bundle, VSD closure and grafting of ascending aorta. Follow-up: significant improvement. Patient 2: 56 year-old female with VSD. PE: 4/6 holosystolic murmur at left sternal border. Echo: DCRV: Mean gradient (MG) 30 mmHg (Fig 1-B), small perimembranous VSD. Ascending aorta: 39 mm. Functionally bicuspid aortic valve, mild AR. Exercise echo: sub-pulmonary resting MG 35, stress MG 52 and PG 90 mmHg. MRI: DCRV with a membrane causing RVOT stenosis. Gene testing for TAAD/Marfan negative. Surgery: VSD closure and resection of RV membrane. Follow up: asymptomatic. Conclusion: DCRV should be considered with an elevated RV systolic pressure and intracavitary gradient. Comprehensive echocardiographic examination of the RV is essential. CMR is useful providing anatomic detail. Surgical correction has successful short and long term outcomes.