IMPLANTABLE DEFIBRILLATOR IN THE LONG QT SYNDROME

A 29-year-old otherwise symptom-free patient had undergone a partial t hyroidectomy 5 years ago followed by an episode of ventricular tachyca rdia and (after lidocaine injection) ventricular fibrillation requirin g external defibrillation. No cause for, the arrhythmias had been foun d at that time. Two subsequent syncopes led to her hospitalization. An asystole occurred while she was being monitored, and during the resus citation there were several periods of ventricular fibrillation, which responded to external defibrillation. Subsequently several episodes o f self-limiting ventricular tachycardia were recorded. A long QT syndr ome with torsade-de-pointes tachycardia was diagnosed on the basis of typical ECG changes (QT interval 545 ms). Extensive diagnostic tests f ailed to find a cause. To prevent further tachycardias she was given p ropranolol, 40 mg three times daily, and an automatic defibrillator wa s implanted as a precaution. But no defibrillator discharge has so far been required (more than 10 months).