Sleep Fainting: A Neurocardiogenic Entity

Fainting is a common clinical presentation, with vagally mediated (neurocardiogenic) causes being the most common for syncope presentation to the emergency room, and for hospital admissions. Classic teaching is that upright posture is a prerequisite for vagally mediated syncope (VMS) and that syncope in the supine position has more sinister causes. We present five patients, three males and two females, with a mean age of 44.4 (range 29-67) years, who presented with VMS in the supine position (sleep fainting). Four patients also had a history of classic upright syncope. Based on their clinical features and thorough investigations, we excluded other causes of loss of consciousness and diagnosed these patients to be having VMS in the supine position (sleep fainting). We further describe the management and follow-up of these patients. Sleep fainting/syncope is a new entity and has to be recognized for appropriate management. A diagnosis can be established if there is clinical suspicion, preserved left ventricular function without evidence of coronary artery disease, no high-risk electrocardiographic evidence of pre-excitation, long or short QT syndrome, Brugada syndrome or arrhythmogenic right ventricular dysplasia, and normal neurological work-up.