Summary

A 24-year-old woman was diagnosed with long QT syndrome (LQTS) because of recurring losses of consciousness. She was implanted with a cardioverter-defibrillator, but losses of consciousness reoccurred. Genetic analysis proved LQTS. An electroencephalogram showed spontaneous generalised spikes and polyspike waves with a 3–4/s frequency. Losses of consciousness ceased only after antiepileptic treatment. We conclude that it may by worthwhile scrutinising patients with LQTS for subtle epileptic activity to find evidence for a cerebral manifestation of a disease thought to be confined to the heart.