[Implantable defibrillator in the long QT syndrome]

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