A 51 male, affected by Tetralogy of Fallot, underwent a left Blalock-Taussig anastomosis at the age of two years and an aorto - right pulmonary artery tube graft when 8 years old. Complete surgical correction was performed at age 21 with closure of the ventricular septal defect and a large patch over the right outflow tract, shunts were discontinued. Then it was well up to 51 years old when he began to suffer shortness of breath with minimal exertion. with ECG evidence of supraventricular tachycardia. Suggestive signs of a typical atrial flutter led to early electrophysiological assesment and successful cavo-tricuspid isthmus ablation was successfully performed. . Echocardiographic and magnetic resonance imaging and ergospirometry provided complete informations on anatomic and hemodynamic conditions but no other interventional procedure was necessary.