Tetralogy Of Fallot

Right ventricular hypertrophy causes the left ventricular apex to be uplifted and cause cardiomegaly. In addition, the pulmonary artery segment shadow, usually noted just above the left atrial appendage shadow is not present due to small pulmonary arteries. This give the characteristic "Boot shape" appearance of the cardiac silhouette.

The pulmonary vasculature is significantly diminished due to decreased pulmonary blood flow.