Vasovagal syncope

Question 1

What is vasovagal syncope?

Answer 1

Loss of consciousness due to a transient drop in blood flow to the brain caused by excessive vagal discharge (activation of the vagus nerve). 

Question 2

What causes vasovagal syncope?

Answer 2

1. Vasovagal syncope is a very common cause of fainting 
2. Can be precipitated by: 
   - Emotions (e.g. fear, severe pain, blood phobia) 
   - Orthostatic stress (e.g. prolonged standing, hot weather) 

Question 3

Summarise the epidemiology of vasovagal syncope

Answer 3

● VERY COMMON
● Syncope (of all causes) affects 40% of people

Question 4

What are the presenting symptoms of vasovagal syncope?

Answer 4

● Loss of consciousness lasting a short time
● Patients may experience vagal symptoms (sweating, dizziness, light-headedness) before passing out
● There may be some twitching of limbs during the blackout
● Recovery is normally very quick

Question 5

What signs of vasovagal syncope can be found on physical examination?

Answer 5

● Usually NO SIGNS
can have:
- Light headed
- Nausea
- Diaphoresis (excessive or abnormal sweating for no apparent reason)
- Bradycardia
- Palpitations

Question 6

What investigations are used to diagnose/ monitor vasovagal syncope?

Answer 6

Investigations are involved with checking for other causes of syncope 
1. 24hr ECG type - check for arrhythmia (may see ventricular tachycardia or a pause) 
2. Echocardiogram - check for outflow obstruction 
3. Lying/standing blood pressure - check for orthostatic hypotension 
4. Fasting blood glucose - check for DM/hypoglycaemia 

Question 7

How is vasovagal syncope managed?

Answer 7

1. Patient education + avoiding triggers
2. Volume expansion → increased dietary salt and electrolyte-rich sports drinks
3. Fludrocortisone