Accessory Tricuspid Valve Leaflet and an Anomalous Muscle Bundle in the Right Ventricular Outflow Tract in a Patient with Double-Outlet Right Ventricle: A Rare Case Report

Double-outlet right ventricle (DORV), a clinically important congenital heart disease, occurs in 1-3% of persons with congenital heart disease. It may occur as an isolated cardiac defect, together with other cardiac lesions, or in association with extracardiac anomalies. Other rare cardiac anomalies include an anomalous muscle bundle (AMB) in the right ventricular outflow tract (RVOT) and an accessory tricuspid valve leaflet. We report a very rare case of concomitant DORV, AMB in the RVOT and accessory tricuspid valve leaflet in a 17-year-old male patient. The patient eventually died from severe decompensated heart failure. To the best of our knowledge, such a case has not been previously reported in the literature.