Vasovagal Syncope

Question 1

def

Answer 1

fainting due to reflex bradycardia and/or peripheral vasodilatation:
provoked by:
-sight of blood
-extreme emotional distress

Question 2

aetiology

Answer 2

mediated through vagus nerve
occurs in response to a trigger which causes a corresponding malfunction in the parts of the nervous system which regular HR + BP
thus causes bradycardia +/ vasodilatation

Question 3

epi

Answer 3

common in adolescents and older adults

Question 4

history

Answer 4

1 Preceding syncope (lasts for seconds before syncope occurs)
-lightheadness
-nausea
-sweating
-closing in of visual fields
2 syncope
-rapid recovery

Question 5

examination

Answer 5

1 bradycardia

2 hypotension

Question 6

what is the most common type of fainting?

Answer 6

vasovagal syncope

Question 7

what are common triggers of vasovagal syncope

Answer 7

1 stress (sight of blood)
2 extreme emotions
3 after urination/bowel movement

Question 8

what is the pathophysiology of vasovagal syncope

Answer 8

the triggering stimulus activates the nucleus tractus solatarii which causes enhancement of PNS (vagal tone) and down regulation of SNS

Question 9

investigations

Answer 9

1 history
-clear description of triggers, symptoms, time course
2 tilt table test
3 implantable loop recorder (records heart electrical activity)
4 24Holter

Question 10

what are the DDx for vasovagal syncope

Answer 10

seizure
vertigo
hypoglycaemia

Question 11

what is the tilt table test

Answer 11

tests for causes of syncope
patient lies flat on a table and is monitored with an ECG, BP monitor
table creates a change in posture from lying to standing