Expansion
Reflex, orthostatic or cardiac, with cardiac the one that kills
Expansion
Three groups
- Reflex (neurally mediated): vasovagal (prodrome of nausea, sweating, tunnel vision, provoked by pain, standing, heat), situational (cough, micturition, defaecation), carotid sinus hypersensitivity. The commonest and benign
- Orthostatic: hypovolaemia, drugs, autonomic failure. Occurs on standing
- Cardiac: arrhythmia (bradyarrhythmia, tachyarrhythmia), structural (aortic stenosis, hypertrophic cardiomyopathy, tamponade), pulmonary embolism, dissection. The group that kills
Red flags for a cardiac cause
- Syncope during exertion or while supine
- No prodrome, so sudden collapse with injury
- Palpitations beforehand
- Family history of sudden cardiac death under 40
- Known structural heart disease or heart failure
- Abnormal ECG
“Exertional, supine or unheralded means cardiac until proven otherwise.”
Every patient needs a 12 lead ECG, a lying and standing blood pressure, and a collateral history from a witness.
Distinguish from seizure: tongue biting at the side, prolonged post-ictal confusion and a slow recovery favour seizure; pallor, rapid recovery and a clear prodrome favour syncope. Brief myoclonic jerks are common in syncope and do not indicate epilepsy.