As with most congenital heart diseases, there is no known cause of pulmonary atresia. The condition is associated with another type of congenital heart defect called a patent ductus arteriosus (PDA). Persons with pulmonary atresia may also have a poorly developed tricuspid valve. They may also have an underdeveloped right ventricle and abnormal blood vessels feeding the heart. Pulmonary atresia may occur with or without a ventricular septal defect (VSD). If the person does not have a VSD, the condition is called pulmonary atresia with intact ventricular septum (PA/IVS). If the person has both problems, the condition is called pulmonary atresia with VSD. This is an extreme form of tetralogy of Fallot. |