Tetralogy of Fallot
Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart defect. The main components of TOF are pulmonary stenosis, right ventricular hypertrophy, an overriding aorta, and a ventricular septal defect. A helpful mnemonic to recall these features is "PROV". The four components of TOF is thought to result from a single defect: anterior malposition of the infundibular septum. Hypoxemic spells, also known as "Tet spells", is a hallmark of severe TOF. Chest radiographs often demonstrate a boot shaped heart, characterized by right ventricular hypertrophy with upturning of the apex. Echocardiography is the diagnostic study of choice. Treatment is typically surgical consisting of a modified Blalock-Taussig procedure or definitive repair.