Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, [9] is a congenital heart defect characterized by four specific cardiac defects. [4] Classically, the four defects are: [4] Pulmonary stenosis, which is narrowing of the exit from the right ventricle;, The American Heart Association explains the congenital heart defect Tetralogy of Fallot in children and adults., What is tetralogy of Fallot (TOF)? Tetralogy of Fallot is a congenital heart defect. It has four characteristics: Ventricular septal defect (VSD): a hole between the two bottom chambers (the ventricles) of the heart that sends blood to the body and lungs., Tetralogy of Fallot is a congenital heart condition (present at birth) that has four issues in your heart. ToF makes it hard to get enough oxygen to your body., Tetralogy of Fallot (TOF) is a combination of four congenital (present at birth) heart defects that affect infants and children. The defects occur together and change the way blood flows through the heart and lungs. TOF occurs in about 1 out of every 2,518 babies born in the U.S. each year., Tetralogy of Fallot is one of the commonest cyanotic heart defects. The severity of cyanosis is determined by the degree of obstruction to pulmonary blood flow. Prevention of cyanotic spells is key for safe anaesthesia. Late complications include arrhythmias, pulmonary regurgitation and right heart failure. Learning objectives..