<unk>  is a congenital heart defect that occurs when the flaps of the<unk><unk>  do not develop or are severely underdeveloped (hypoplasia) resulting in aneurysms (dilation) of the<unk>  arteries and softening of the trachea and bronchi (tracheobronchomalacia). Usually,<unk>  occurs together with other congenital heart defects, most commonly ventricular septal defect and right ventricular outflow tract obstruction. It is sometimes considered a variant of Tetralogy of Fallot.
Absent pulmonary valve syndrome
Holiday heart syndrome
Hypoplastic left heart syndrome
Hypoplastic right heart syndrome
Lettuce big-vein disease
Bilharzial cor pulmonale
Tricuspid atresia
Double outlet right ventricle