[The idiopathic QT syndrome as the cause of epileptic and nonepileptic seizures].

The long QT syndrome (LQTS) is characterized by a pathological lengthening of the corrected QT interval on the surface ECG and the occurrence of syncopal attacks, sometimes presenting as a seizure disorder. They are caused by ventricular tachycardia of the torsade de pointes type, an arrhythmia that is also responsible for the high incidence of sudden death among these patients. Besides the acquired forms of LQTS which are transient (e.g. therapy with QT-prolonging drugs), congenital variants (Romano-Ward syndrome, Jervell/Lange-Nielsen syndrome, sporadic form) can occur as well. The latter mostly become manifest during childhood or adolescence. Because the syndrome is rare, it is often not included in the primary differential diagnosis of syncope. Thus, misinterpretation as epilepsy may occur. Especially if siblings are affected, a genetic epilepsy may be diagnosed. However, the correct diagnosis can be made by standard ECG methods. Early recognition of the syndrome is very importance because of prognostic and therapeutic consequences. In this article, two cases of idiopathic LQTS are presented. Problems regarding differential diagnosis and therapy are discussed.