Vasovagal Syncope

Reflex bradycardia and vasodilatation causing a brief loss of consciousness. It is the commonest cause of a faint and it is benign — which is exactly why it is dangerous as a label. The value of this pathway is the discriminators that say it is not…

Prodrome, trigger, quick recovery — or none of those, and think cardiac

The pathway

1 · Get the story from a witness if there is one

Before: what were they doing, and was there a prodrome?
During: how long, what colour, any movements, any injury, incontinence, tongue biting?
After: how quickly were they properly back to normal?
The witness account is worth more than any test you will order tonight

2 · What a vasovagal faint looks like

A prodrome: nausea, warmth, sweating, greying or tunnelling vision, ringing in the ears
A trigger: prolonged standing, heat, pain, the sight of blood, coughing, micturition, a large meal
Upright at the time
Rapid, complete recovery — orientated within a minute or two, though often tired afterwards
Brief myoclonic jerks are common and do not make it a seizure

3 · ⚠ The features that say cardiac instead

Syncope occurring DURING exertion — the most important single red flag. Syncope shortly after stopping exercise can still be vasovagal
Syncope while sitting or lying
No prodrome — sudden, with injury from the fall
Palpitations before it, or chest pain
Known structural heart disease or heart failure
Family history of sudden cardiac death under 40, or of inherited heart disease
An abnormal ECG

4 · The ECG is not optional

Every syncope gets a 12-lead ECG. It is the cheapest way to find the dangerous causes
Look for: long or short QT, Brugada pattern, delta wave (WPW), complete heart block or bifascicular block, pathological Q waves, left ventricular hypertrophy, T wave inversion in the right praecordial leads
If you are not sure, get it reviewed rather than filing it as normal
Lying and standing blood pressure where clinically appropriate — the ECG is the universal test, this one is not

5 · Look for the other common causes before settling

Orthostatic hypotension — a drop on standing, commonly from antihypertensives, alpha-blockers, diuretics, antidepressants
Medication review is the intervention in a great many older fainters
Bleeding — a GI bleed or a ruptured ectopic can present as a faint
Was it a seizure? Tongue biting at the side, prolonged confusion afterwards, incontinence
Hypoglycaemia — check the glucose

6 · Disposal and what to say

Typical vasovagal with a normal ECG and examination — reassurance, trigger avoidance, fluids and salt if appropriate, counter-pressure manoeuvres, and safety-netting
Any red flag — do not discharge without a senior or cardiology discussion
Driving: tell the patient there are DVLA rules, and that they depend on the cause and the pattern — check the current guidance rather than guessing
Injury from the faint needs its own survey

Drugs

Drug	Dose	Route	Notes
Culprit antihypertensives	Review and reduce	—	In orthostatic syncope, the medication review is the treatment.
Fluids and salt	As appropriate to the patient	PO	Reasonable advice in recurrent vasovagal syncope. Not for those with heart failure or renal disease.
Counter-pressure manoeuvres	Taught, not prescribed	—	Leg crossing, handgrip and arm tensing at the first prodrome. Genuinely effective and costs nothing.

When to escalate

Syncope during exertion — cardiology before discharge, every time,Syncope while sitting or lying, or with no prodrome — same,Abnormal ECG, or one you are not certain about — get it reviewed, do not file it,Family history of sudden death under 40 — cardiology, and it changes the family's follow-up too

Reference: NICE CG109 transient loss of consciousness in over-16s; ESC guidelines on syncope. DVLA guidance changes — check the current version rather than quoting from memory.

This page is the reference half

The app adds what a web page cannot: a VINDICATE differential builder, worked on-call scenarios with full A–E findings, recall practice, and all of it offline.