Vasovagal syncope

Question 1

define vasovagal syncope?

Answer 1

loss of consciousness due to transient drop in blood flow to the brain caused by excessive vagal discharge

Question 2

explain the aetiology/ risk factors of vasovagal syncope?

Answer 2

precipitated by

emotions ( fear, severe pain, blood phobia)

orthostatic stress ( 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, diminished hearing) before passing out

Pallor

Slow HR at the time of the syncope

There may be some twitching of limbs during the blackout

Recovery is normally very quick

Fatigue after episode – important clue to vasovagal event

Question 5

what are the signs of vasovagal on physical examination?

Answer 5

NO SIGNS

Question 6

what are the appropriate investigations for vasovagal syncope?

Answer 6

Check for other causes of syncope

ECG - check for arrhythmia, AV block, bradycardia, asystole, BBB

Hb – rule out syncope caused by anaemia

Serum cortisol – rule out syncope caused by adrenal insufficiency

Echocardiogram - check for outflow obstruction

U&Es – rule out syncope caused by dehydration

Lying/standing blood pressure - check for orthostatic hypotension

Fasting blood glucose - check for DM/hypoglycaemia

Preg test

Cardiac enzymes – rule out MI if clinical suspicion

D-dimer – rule out PE if clinical suspicion

Tilt-table test may be done if the is a suspicion but med history is not convincing on its own