A 43 year old man presents following a sudden faint while walking home from work. There were no prodromal symptoms, the episode lasted for only a couple of minutes, and he was not confused or drowsy afterwards.
His is otherwise asymptomatic, while his medical history and family histories are unremarkable.
He is not on any medications, does not smoke, and only drinks socially. There is no history of substance abuse.
His full blood count, random capillary glucose, serum electrolytes, and chest x-ray are normal, as are serial ECGs.