Syncope Flashcards
What is syncope?
A transient loss of consciousness due to global cerebral hypoperfusion.
Rapid onset, short duration & spontaneous complete recovery.
What is the most common cause of syncope?
Vasovagal syncope - ‘fainting’.
What happens in vasovagal syncope?
A sudden drop in BP leading to a disruption of blood flow to the brain.
What is vasovagal syncope often triggered by?
Emotional stress, pain, standing for long periods.
Pathophysiology in vasovagal syncope
1) Vagus nerve receives a strong stimulus e.g. emotional event, change in temp, painful sensation
2) This stimulates parasympathetic nervous system
3) Parasympathetic activation counteracts the sympathetic nervous system (this eeps the smooth muscles in blood vessels constricted)
4) Vessels delivering blood to brain relax
5) BP in cerebral circulation drops
6) Hypoperfusion of brain tissue –> faint
What is the ‘prodrome’ in vasovagal syncope?
When patients often remember the event and can recall how they felt prior to fainting.
How do patients typically describe feeling before fainting?
- hot or clammy
- sweaty
- dizzy or lightheaded
- heavy
- vision going blurry or dark
- headache
What may person look like during episode of vasovagal syncope?
- Suddenly losing consciousness and falling to the ground
- Unconscious on the ground for a few seconds to a minute as blood returns to their brain
- There may be some twitching, shaking or convulsion activity, which can be confused with a seizure
- May be incontinence
Describe post-episode in vasovagal syncope vs seizure
Vasovagal syncope: may be a bit groggy following a faint but quick recovery
Seizure: postictal period of prolonged confusion, drowsiness, irritability and disorientation.
1ary causes of syncope (simple fainting)?
1) dehydration
2) missing meals
3) extended standing in warm environment e..g school assembly
4) vasovagal response to a stimuli e.g. sudden surprise, pain, sight of blood
2ary causes of syncope (i.e. underlying conditions)?
- Hypoglycaemia
- Dehydration
- Anaemia
- Infection
- Anaphylaxis
- Arrhythmias
- Valvular heart disease
- Hypertrophic obstructive cardiomyopathy
What is cardiac syncope?
This type of syncope occurs due to a problem with the heart’s electrical system, such as an arrhythmia or heart block.
It is more common in older adults and those with a history of heart disease.
What is orthostatic hypotension?
This is a sudden drop in blood pressure that occurs when a person stands up from a sitting or lying position.
It can be caused by dehydration, medication side effects, or underlying medical conditions.
What is neurological syncope?
This type of syncope occurs due to a problem with the brain or nervous system, such as a seizure disorder or stroke.
It is less common than the other types of syncope but should be considered in patients with a history of neurological conditions.
