Syncope + Collapse

Question 1

What is syncope?

Answer 1

Temporary LOC due to disrupted blood flow to the brain

Question 2

What is a vasovagal episode and what can cause it?

Answer 2

Problem with autonomic NS regulation of BF to brain due to excessive vagal nerve stimulation which leads to increased activity of parasympathetic NS
-leads to vasodilation of BV which causes drop in cerebral circulation BP

Causes:

• emotional event
• painful stimuli
• change in temp
• dehydrations
• blood

Question 3

What are the classical prodrome symptoms (feelings prior to vasovagal episode)?

Answer 3

NOTE: symptoms associated with autonomic dysfunction w/ predominant activity of PNS

• hot or clammy
• sweating
• dizzy or light headed
• blurry vision
• headache

Question 4

What is the common signs on examination for vasovagal episode?

Answer 4

Bradycardia and hypotensive and pallor

I.e. associated with increased parasympathetic activity and decreased blood flow

Question 5

What are the key differentials for a vasovagal episode?

Answer 5

Seizure

Inferior MI= can have very similar presentation

Postural hypotension

Arrhythmia

AS= collapse can be the first presentation of AS or sign of severe AS

Low Hb

Question 6

What are the causes of syncope?

Answer 6

Primary= simple fainting

• dehydration i..e hypovolemic
• extended standing
• vasovagal

Secondary

• hypoglycaemia
• anaemia
• infection
• anaphylaxis
• arrhythmias
• AS or other valvular heart disease
• hypertrophic obstructive cardiomyopathy

Question 7

Why is a stroke unlikely to be associated with a classical syncopal episode?

Answer 7

It would have to be a significant infarct to the posterior cerebral circulation supplying the reticular activating system in order to cause LOC

I.e. would not wake up after collapse

Question 8

What are the key ways to differentiate between a syncopal episode and a seizure?

Answer 8

Pre-seizures

• no aura in syncope
• sweating in syncope
• loss of tone rather than increased tone (tonic clonic)
• return to normal state shortly after event i.e. no post-ictal event in syncope
• short duration (seizure can last more than 5 mins)

Question 9

What investigations would you do in someone presenting with collapse/syncope?

Answer 9

Bedside:

• cardiovascular examination
• Neuro examination
• lying and standing BP= if query postural hypotension
• ECG= arrhythmias, LVH signs in AS

Bloods:

• FBC= anaemia
• U+Es= electrolytes disturbance might be causing the arrhythmias i.e. hyperkalaemia
• Troponins= query inferior MI
• Blood glucose= hypoglycaemic

Imaging:
-Echo= if structural heart defect suspected i.e. valvular disease

Special tests:
-REVEAL (24/48/72hr ECG monitoring)= can help to detect paroxysmal arrhythmias

Question 10

What are the differential diagnosis for someone presenting with suddent collapse or blackout?

Answer 10

Faint= vasovagal episode 
Seizure 
Cardiac syncope 
Cataplexy 
-paralysis whilst remaining conscious 
-context of narcolepsy 
Hypoglycaemic attack

Question 11

What someone has experienced a collapse, what is the structure of the history to best understand what has happened?

Answer 11

Ask if any witness so can assess collateral history

BEFORE

• dizzy or lightheaded
• unwell recently i.e. infective symptoms
• palpitations or chest pain
• change in position i.e. sitting to standing
• experince an aura

DURING

• did hit head
• LOC?
• when did they come round (i.e. if in same place then less likely to be seizure as tend to be longer and wake up in ambulence)
• what do they remember i.e. can be way to assess if actually lost consciouness if there are gaps between events
• what was the mechanims of fall

AFTER

• weakness or pain or sore muscles
• where they able to get up (especially in the elderly)
• where they confused after= seizure?
• had they experienced incontinence
• had they vomited