We report a 81 years old female with a severe aortic insufficiency, treated with diuretics and antidepressants admitted due to recurrent syncopal episodes. During the first syncopal episode, an atrioventricular block was detected and an endocavitary demand pacemaker implanted. Two years later, she had a new syncope without evidences of pacemaker failure. The EKG during pacemaker rhythm showed a prolonged QT interval. During hospital monitoring, she presented a self limited polymorphic ventricular tachycardia (Torsade de Pointes). Consequently, the pacemaker was programmed at a greater frequency, and the QT interval shortened from 0.73 to 0.56 sec. Thereafter, the patient no longer had tachycardia or syncopal episodes, after one year of follow up.