Which of the following statements about double-outlet right ventricle are true?

A. A VSD is usually present.

C. Patients with double-outlet right ventricle and a subaortic VSD usually have pulmonary stenosis.

D. Patients with double-outlet right ventricle with a subpulmonary VSD (Taussig-Bing malformation) tend to mimic patients with transposition of the great arteries and VSD in their presentation and natural history. 

DISCUSSION: A VSD is usually present in patients with double-outlet right ventricle and is the only outlet from the left ventricle. Both great arteries may arise totally from the right ventricle, or one or both may overlie the ventricular septum immediately above the VSD. To categorize the heart as having a double-outlet right ventricle, more than 50% of each great artery must arise from the right ventricle. In the Taussig-Bing type of double-outlet right ventricle, the VSD is related to the pulmonary valve annulus and is termed a subpulmonary defect. Additional morphologic characteristics peculiar to this entity have been described. Most patients with double-outlet right ventricle and a subaortic VSD have concomitant pulmonary stenosis that protects the lungs from pulmonary vascular disease and also results in a clinical course similar to that of patients with tetralogy of Fallot. In the absence of pulmonary stenosis the presentation, clinical course, and natural history of the Taussig-Bing malformation are similar to those of transposition of the great arteries with VSD. Cyanosis is present, usually from birth, since streaming directs the desaturated systemic venous return toward the aorta and the oxygenated left ventricular blood toward the pulmonary artery. These patients tend to develop early congestive heart failure and can develop severe pulmonary vascular disease early in life. They usually experience symptoms within the first few months of life.