Vasovagal Faints

Question 1

Definition

Answer 1

Vasovagal (neuro cardiogenic syncope) is due to reflex bradyc possibly with peripheral vasolidation provoked by emotion, pain, fear, or long standing (orthostatic stress), temperature, not eating/drinking. Lightheadedness or LOC.
Onset over a few seconds and often preceded by pallor, nausea, sweating, closing visual fields (pre syncope).
Requires LOC due to poor brain perfusion. And transient.
Cannot occur if lying down.

Question 2

Symptoms

Answer 2

Fall, LOC for a couple of mins.
Possible brief clinic jerking but no stiffening. 
Slow weak pulse
Dilated pupils
Rarely urinary incontinence.
No tongue biting
Rapid recovery
Before- pallor, light headed, tunnel vision, nausea, warm, clammy, yawning, blurred vision.

Question 3

Differentials

Answer 3

Situation syncope eg cough, effort, micturition.
Carotid sinus syncope- reflex brady due to hypersensitive baroRs. 
Neuropathy
Arrhythmia
Orthostatic hypotension 
Arterial insufficiency
Hypovolaemia
Alcohol toxicity
Epilsepsy
Hyperventilation
Stokes adams attacks- transient arrhythmia. 
Drop attack- sudden leg weakness. 
Hypoglycaemia. 
Vertigo
Syncopal migraine
Pseudoseizure
CSF flow disruption
Balance issue
Anaemia

Question 4

Aetiology

Answer 4

Slowing or temporary stop in HR=disruption brain BS.
Increased PNS output due to direct stimulation (micturition, defacation, abdo pain etc) or as reflex response to SNS stimulation (eg seeing blood, abrupt stop exercise).

Results in arterial dilation and inhibition of SAN and AVN activity.
So causes transient decrease BP.
Due to association with vagal output, they are often associated with nausea, diaphoresis, salivation.

Question 5

Management

Answer 5

Behavioural eg avoid triggers, compression stockings, hydration, salt intake.
Acutely- lie down with feet up, while isometric hand exercises.
Drugs eg BB, MC, alpha agonists.
Advise to look out for warning signs and tell those around them.

Question 6

Explanation

Answer 6

• when we faint its because not enough blood is reaching the brain temporarily. In vasovagal faints this is because some kind of stimulus cause our nervous system to trigger a lowering of the heart rate and dilation of blood vessels. This makes our blood pressure lower and means less blood test to the brain. The triggers can be emotional, pain, standing up too long, or stopping exercise.
• the faint comes on quite suddenly and is often preceded by going pale, feeling sick, losing vision, sweating. Normally you lose conciousness and fall over but regain conciousness after a few seconds and recover quite quickly. It can be dangerous though of course falling over in unexpected way so there is a risk of injury.
• lifestyle changes can include avoiding trigger, wearing compression stockings, keeping well hydrated. Also it is good to try to recognise the signs before the faint happens and warn people around you. Immediately after the faint it is good to raise your legs adn do some hand movements.
• drug treatment is only given if the problem persists. So we can give drugs to stop your heart rate falling so low and to stop your bloop pressure dropping.