Syncope Flashcards
What is a transient loss of consciousness?
a state of real or apparent loss of consciousness with loss of awareness, characterised by amnesia for the period of unconsciousness, loss of motor control, loss of responsiveness and a short duration
causes of TLOC?
- head trauma
- syncope
- epileptic seizures
what is syncope?
TLOC due to cerebral hypo perfusion, characterised by rapid onset, short duration and spontaneous complete recovery
what are the three types of syncope
- reflex
- orthostatic hypotension
- cardiac syncope
what is reflex syncope?
failure in autoregulation of blood pressure resulting in cerebral hypoperfusion
what causes cerebral hypo perfusion in reflex syncope?
- reflex causes vagal stimulation causing bradycardia as well as inhibition of sympathetic activity of blood vessels
- this causes reduced MAP and can cause cerebral hypo perfusion.
what are the different types of reflex syncope?
- vasovagal syncope
- situational syncope
- carotid sinus syncope
what is syncope triggered by in vasovagal reflex syncope?
emotional distress
how can syncope be avoided when vasovagal is the cause?
- lying down
- raising or crossing of legs
what is situational reflex syncope?
faint during or immediately after a specific trigger e.g - cough or swallowing
what causes carotid sinus syncope?
- triggered by mechanical manipulation of the neck
- associated with older patients with a history of atherosclerosis
treatment for carotid sinus reflex syncope?
permanent cardiac pacing.
what is postural hypotension?
the failure of baroreceptor responses to gravitational shifts in the blood when moving from horizontal to vertical position
risk factors for postural hypotension?
- age
- medications
- prolonged bed rest
- certain diseases
what are the values indicative of a positive result for postural hypotension?
a positive result indicated by.a drop within 3 minutes of:
- systolic BP of at least 20mmhg
- a drop in diastolic blood pressure of at least 10mmhg
symptoms of cerebral hypo perfusion?
- lightheadedness
- dizziness
- blurred vision
- faintness
what causes cardiac syncope?
a cardiac event resulting in a sudden drop in cardiac ouput.
what can cause cardiac syncope?
- arrhythmias
- MI
- Structural cardiac disease
- other cardiovascular disease
initial evaluation of TLOC?
- a careful history
- full physical examination
- orthostatic blood pressure measurement
- 12 lead ECG
