Tetralogy of Fallot


Tetralogy of Fallot (TOF) is a congenital cardiovascular anomaly that consists of right ventricular outflow tract obstruction, right ventricular hypertrophy, high ventricular septal defect (VSD) and an overriding aorta. Hemodynamically, the critical component of the anomaly is the right ventricular outflow tract obstruction which may come in a range of presentations from mild pulmonary stenosis to pulmonary atresia. In the past, the patient in this case underwent palliative shunt surgery (modified Blalock-Thomas-Taussig shunt) to improve pulmonary circulation and to prepare the pulmonary arteries for total corrective surgery. However, peripheral stenosis is present at the proximal left pulmonary artery which resulted to unequal blood flow (preferential flow to the right lung and decreased flow into the left lung) which is evident in the accompanying chest radiograph.