[Atypical form of long-QT syndrome--a case report]

An unusual case of familial Long QT syndrome is reported. After a longstanding symptom free interval this eight year old girl experienced multiple episodes of malignant ventricular arrhythmias including ventricular tachycardias of the torsades-de-pointes type and ventricular flutter. The treatment with beta- and alpha-blocking agents, phenytoin, calcium antagonists, clonidine and magnesium in increasing doses and varying combinations was unsuccessful. A left sided cardiac sympathectomy failed also to control the life threatening ventricular arrhythmias and to decrease the relative high mean heart rate. Finally a consecutive right cardiac sympathetic denervation in combination with an experimental class I antiarrhythmic agent led to a subjective and objective improvement in the patient's condition which allowed discharge from hospital. Despite a symptom free interval of four months and nearly normalized Holter ECG results the longterm prognosis remains unclear. This unusual case discloses interesting features, because 1) it supports the theory of an intracardiac cellular anomaly rather than the imbalance hypothesis, 2. chronic beta-blocker treatment possibly resulted in an up-regulation of beta-adrenergic receptors which made beta-blocking agents ineffective despite high doses, and 3. an consecutive right sided cardiac sympathectomy resulting in bilateral cardiac sympathetic denervation had to be done-an intervention which is seldom performed in the Long QT syndrome.