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.

Question 2

Describe the aetiology of Vasovagal Syncope

Answer 2

Can be precipitated by:
Emotions (e.g. fear, severe pain, blood phobia)
Orthostatic stress (e.g. prolonged standing, hot weather)

Question 3

Describe the epidemiology of Vasovagal Syncope

Answer 3

VERY COMMON

Syncope (of all causes) affects 40% of people

Question 4

List 3 symptoms of Vasovagal Syncope

Answer 4

LOC lasting a short time  
Vagal symptoms (sweating, dizziness, light-headedness, diminished hearing) before passing out  
Fatigue after episode: important clue to vasovagal event

Question 5

List 4 signs of Vasovagal Syncope

Answer 5

Usually NO SIGNS 
Pallor 
Slow HR at the time of the syncope 
May be some twitching of limbs during the blackout  
Recovery is normally very quick

Question 6

What bedside investigations may be performed in suspected Vasovagal Syncope to rule out other causes?

Answer 6

LSBP: orthostatic hypotension
ECG: arrhythmia, AV block, bradycardia, asystole, BBB
Preg test

Question 7

What bloods may be taken in suspected Vasovagal Syncope to rule out other causes?

Answer 7

Hb: anaemia 
U+Es: dehydration  
Serum cortisol: adrenal insufficiency  
Fasting blood glucose: DM/ hypoglycaemia
Cardiac enzymes: MI  
D-dimer: PE

Question 8

What further investigations may be performed in suspected Vasovagal Syncope to rule out other causes?

Answer 8

Echo: outflow obstruction

Tilt-table test: if hx is not convincing on its own

Question 9

What is the purpose of investigations in suspected Vasovagal syncope?

Answer 9

Identifying other causes of syncope