Severe cardioinhibitory vasovagal syncope in sleep and supine posture

Severe cardioinhibitory vasovagal syndrome is characterised by syncope accompanied by cardiac asystole which may lead clinically to seizure-like motor activity. Vasovagal syncope usually occurs in erect posture and is often provoked by emotional or physical triggers. We report two patients who presented with severe cardioinhibitory vasovagal syncope accompanied by cardiac asystole resulting in seizure-like motor manifestations in sleep and supine posture. Both cases were initially diagnosed as epilepsy and treated with antiepileptic drugs. We discuss the putative mechanisms of this rare condition and its potential for misdiagnosis as epilepsy.