Cardiac tachyarrhythmias in hereditary long QT syndromes presenting as a seizure disorder.

Patients with hereditary long QT disorders--Romano-Ward Syndrome and Jervell Lange-Nielsen Syndrome--sometimes present with seizures due to cardiac tachyarrhythmias. Two such patients are presented, emphasizing diagnostic clues--syncope, seizures with onset in early life, precipitation of attacks by emotional or physical stress, positive family history of sudden death and/or seizures, normal EEG and prolonged QT interval on ECG. Treatment is usually with adequate doses of sympathetic betablockers.