Stress-induced polymorphous ventricular tachyarrhythmias in two brothers: unusual pattern of inheritance in the long QT syndrome.

ABSTRACT

Two brothers, 10 and 9 years old, are reported who were treated for years with antiepileptic drugs until the cardiac origin of their syncopal attacks was discovered. Our findings are consistent with the diagnosis of long QT syndrome, although no other family members are affected and only intermittent and mostly borderline QT prolongation could be found. Diagnostic difficulties and genetic implications are discussed.