These lesions are often accompanied by cyanosis. Examples include:
Most common form of cyanotic congenital heart disease. The four main components are (1) malaligned VSD, (2) obstruction to RV outflow, (3) aorta that overrides the VSD, and (4) RV hypertrophy (RVH). Degree of RV outflow obstruction largely determines clinical presentation; when severe, the large right-to-left shunt causes cyanosis and systemic hypoxemia. ECG shows RVH. CXR demonstrates “boot-shaped” heart with prominent RV. Echocardiography delineates VSD, overriding aorta, and RVH and quantitates degree of RV outflow obstruction. Current surgical treatment strategies include primary repair in infancy. Complications following repair include pulmonary regurgitation with RV enlargement and/or RV outflow tract obstruction, and LV dysfunction, especially in adults repaired later in life and in those with prior palliative shunt surgery.
Complete Transposition of the Great Arteries (Tga) 
Accounts for 10% of pts with cyanotic congenital heart disease. Aorta and pulmonary artery arise abnormally from the right and left ventricles respectively, creating two separate parallel circulations; a communication must exist between the two sides (ASD, PDA, or VSD) to sustain life. Development of RV dysfunction and heart failure are common by the third decade. Echocardiography reveals the aberrant anatomy. Treatment of the common D-loop form of TGA involves an arterial switch procedure, with translocation of the coronary arteries.
Abnormal downward placement of tricuspid valve within the RV; tricuspid regurgitation, hypoplasia of RV, and a right-to-left shunt are common. Twenty percent of pts have Wolff-Parkinson White ECG pattern. Echocardiography shows apical displacement of tricuspid septal leaflet, abnormal RV size, and quantitates degree of tricuspid regurgitation. Treatment includes surgical tricuspid valve repair/replacement and closure of associated ASDs.