focal or complete absence of the right ventricular myocardium which results in the right ventricle becoming a thin-walled fibroelastic bag which contracts poorly. There is right heart failure. Often tricuspid insufficiency is also present. This is a rare anomaly which presents in infancy with cyanosis.
On chest radiographs the right heart is enlarged with diminished pulmonary vasculature. Echocardiogram or angiocardiography will demonstrate that the tricuspid valve is in the normal position but with regurgitation.