Tetralogy of Fallot (ToF) occurs in about 4 births/1000/year and represents about one tenth of all congenital heart diseases. Nowadays 86% of patients reach adulthood with corrective surgery. Before the 1980s, these patients were treated only with "surgical palliation", which consisted in the creation of a systemic to pulmonary artery shunt or a pulmonary valvulotomy, whereas after the introduction of extracorporeal circulation, corrective surgery is performed electively between 3 and 6 months of life. After repair patients during their life may develop hemodynamic lesions, including right ventricular outflow tract dysfunction, and arrhythmias which can occur in over 30% of cases. It is estimated that these patients present a risk of sudden death of 0.2%/year. Therefore, for the prevention and treatment of arrhythmic events, a periodic follow-up in specialized centres for adult congenital heart disease is mandatory, because most often arrhythmias are triggered by the presence of hemodynamic lesions, first of all pulmonary regurgitation.