Week 20a - Palpitations and Syncope Flashcards
what is syncope
loss of consciousness due to reduced cerebral perfusion
may also be used to refer to any transient loss of consciousness
what does pre-syncope refer to
light headedness when someone feels they may be about to lose consciousness
key elements in syncope history
ensure understanding of what patient means
details description of timing, what patient was doing, what they experienced, how long they were unconscious for and how they felt afterwards
obtain witness account if possible
past medical history
common causes of syncope
CV syncope - arrhythmia, structural heart disease
postural or orthostatic hypotension
neurally mediated - epilepsy
vasovagal/neural reflex syncope
drug intoxication
hypoglycaemia
normal rhythms
sinus rhythm
sinus tachycardia
sinus bradycardia
sinus arrhythmia
when will sinus tachy occur
when exercising
fever/infection
dehydration
when will sinus brady occur
at rest (young people)
when will sinus arrhythmia occur
changes in heart rate due to respiration
common arrhythmias - too fast
atrial fibrillation - most common clinical arrhythmia
ventricular tachy
common arrhythmias - too slow
heart block
common arrhythmias - intermittent
supraventricular tachy
paroxysmal AF
ectopic beats - most common arrhythmia
supraventricular tachy (SVT)
intermittent rapid tachy with abrupt onset anf offset
narrow complex tachy
presentation of SVT
palpitations
light headedness
nausea
chest pain
SOB
usually haemodynamically stable
treatment of SVT
activation of vagus nerve in ANS would increase blockade at AV node
- vagus nerve parasympathetic acetylcholine acting on muscarinic receptors
- can be activated by carotid sinus massage, Valsalva manoeuvre, cold water on face, or modified Valsalva maoeuvre
if vagal manoeuvres dont work, give IV adenosine - slows conduction through AV node
treatment of SVT
activation of vagus nerve in ANS would increase blockade at AV node
- vagus nerve parasympathetic acetylcholine acting on muscarinic receptors
- can be activated by carotid sinus massage, Valsalva manoeuvre, cold water on face, or modified Valsalva maoeuvre
if vagal manoeuvres dont work, give IV adenosine - slows conduction through AV node
ventricular tachy
normally comes with underlying heart disease
broad complex tachy
presentation of ventricular tachy
palpitations
chest pain
SOB
syncope
treatment of ventricular tachy
if unconscious, low BP
- urgent synchronised DC cardioversion
- synchronised to R wave
- medical emergency
stable patients may get rapidly worse so need urgent cardiology input
first degree heart block
conduction slowed from atrium to ventricle
second degree heart block
some beats not conducted from atrium to ventricle
complete (third degree) heart block
no conduction from atrium to ventricle
P waves and QRS complex dissociated
usually affects AV node
presentation of complete heart block
syncope and pre syncope
fatigue
SOB
cardiac arrest
usually underlying heart disease
treatment of complete heart block
vagus nerve in ANS slows conduction at AV node
vagus nerve, parasympathetic, muscarinic cholinergic agonis
treatment involves muscarinic cholinergic antagoinst - atropine
atropine only works short term
definitive treatment involves pacemakes
atrial fibrillation
most common sustained cardiac arrhythmia
lifetime risk over age 40 is 25%
no regular P waves, irregular QRS complex
atrial electrical activity randomly transmitted to ventricle
pulse normally irregularly irregular
presentation of AF
incidental finding
palpitations
SOB
fatigue
can be made worse by alcohol
rate control of AF
increase block at AV node
- beta adrenergic receptor blockers e.g. bisoprolol
- calcium channel antagonist e.g. diltiazem
AF and stroke
clot forms in fibrillating left atrium
emboli can then pass to cerebral circulation
risk of stroke calculated using CHA2DS2-VASc score
stroke prevention
offer anticoagulation
apixaban
rivaroxaban
warfarin
