Tetralogy of fallot with absent pulmonary valve

Congenital absence of pulmonary valve syndrome (APV) represents a fascinating and unique variant of congenital heart disease. It was Chever in 1847 who first described this unique structural heart defect. The anatomic features consist of an incompletely formed, rudimentary pulmonary valve that is both stenotic and regurgitant, massively dilated pulmonary arteries and a large malaligned outlet ventricular septal defect. There is an association of this defect with Tetralogy of Fallot (ToF) due to which this condition is often referred to as Tetralogy of Fallot/absent pulmonary valve syndrome. Another characteristic feature is that there is virtually always absence of a patent ductus arteriosus. That has been hypothesized as being responsible for the pathogenesis of pulmonary artery dysplasia. ¹

APV syndrome is an extremely rare entity. It occurs in only 2.5% of patients diagnosed with ToF and in a 75% of these patients 22q11 deletion is identified.