A 71-year-old man with atrial fibrillation is seen in clinic following an episode of syncope. He describes getting a poor night’s sleep and, as he got out of bed in the morning, feeling dizzy for a couple of seconds before the lights dimmed around him. He was woken a couple of seconds later by his wife who had witnessed the event. She says he went pale and fell to the floor and his arms and legs jerked. After waking, he was shaken but was ‘back to normal’ a few minutes after the event. His medication includes aspirin, atenolol and frusemide. What is the most likely diagnosis?
A. Vasovagal syncope
B. Orthostatic hypotension
C. Cardiogenic syncope
D. Transient ischaemic attack (TIA)
(B) This man most likely experienced an episode of orthostatic or postural hypotension (B) where syncope occurs as a result of reduced cerebral perfusion as the patient moves from lying to standing. Symptoms are similar to vasovagal in that the patient may become pale and describe ‘the lights or sound dimming’. Perfusion is restored after the patient collapses and unconsciousness lasts no more than seconds or a couple of minutes with full recovery. However, vasovagal epsiodes (A) can be brought on by sleep or food deprivation, hot or emotional environments, Valsalva manoeuvre (such as straining) and are not as closely related to position. Syncope while lying down is more suggestive of cardiac syncope or seizure activity. It is important to rule out cardiac causes of syncope (C) which may be heralded by chest pain or palpitations. Arrhythmias or aortic stenosis may be the underlying cause. TIAs (D) are a very rare cause of syncope. Seizures (E) may be triggered by lack of sleep. They may be heralded by an aura, typically visual or olfactory. There may be urinary incontinence, tonic-clonic movements, tongue-biting and cyanosis during the event. However, jerky movements may occur in syncope of any cause. This alone does not equate to a seizure.