ABSTRACT
The tetralogy of Fallot (TOF) defect originates from a deviation of the infundibular septum to the right and anterocephalad, resulting in a hypoplasia of the right ventricular outflow tract and the pulmonary artery system, a subaortic malalignment ventricular septal defect (VSD), and an aortic overriding. About 25% of patients with TOF have a right-side aortic arch, frequently seen in patients with TOF and microdelection on chromosome 22q11. Critical considerations in unoperated TOF are the size of the VSD, shunt direction and amount, the severity of the Right ventricular outflow tract obstruction, and the degree of pulmonary artery hypoplasia. TOF is the most common cyanotic cardiac anomaly in adulthood, present in 4–10% of all congenital heart diseases. At a time when surgery was unavailable, only 11% of TOF patients survived beyond 20 years of age, with only 3% of patients living to 40 years of age.
