arrythmias Flashcards
what is an arrythmia
abnormal heart rythm
why do arrithmyas happen
interuption to normal electrical signals that coordinate contraction of heart muscle
how can the 4 cardiac arrest rhythms be classified
shockable - defib may be effective
non-shockable
cardiac arrest rhythms: shockable rhythms
ventricular tachycardia
ventricular fibrillation
cardiac arrest rhythms: non-shockable
pulseless electrical activity (all electrical activity except VF/VT, incl sinus rhythm without pulse)
asystole
tachycardia treatment summary: unstable patient
- consider up to 3 synchronised shocks
- consider consider amiodarone infusion
tachycardia treatment summary: stable patient with narrow QRS complex
AF - beta blocker or CCB
atrial flutter - beta blocker
SVT: vagal manouvers, adenosine
tachycardia treatment summary: stable patient w broad QRS
VT or unclear - amiodarone infusion
SVT w bundle branch block - treat as per normal SVT
atrial flutter
caused by a re-enterant rhythm in either atrium
electrical signal re-circulates in a self-perpetuating loop due to extra pathway
signal goes round and round without interuption
atrial flutter: atrial and ventricular bpm
atrial contraction 300bpm
signal makes way to ventricles every 2nd lap due to long AV node refractory period - 150bpm ventricular contraction
atrial flutter: ECG
‘sawtooth appearance’
p wave after p wave
atrial flutter: assoc conditions
htn
IHD
cardiomyopathy
thyrotoxicosis
atrial flutter: Mx
rate/rhythm control - beta blockers or cardioverison
treat underlying condition
radiofrequency ablation of re-enterant system
anticoagulation based on CHADVASC
supraventricular tachycardia
electrical signal re-entering atria from ventricles
- electrical signal finds way back from v to atria
- once signal back in atria it travels back through AV node –> v contraction
- self-perpetuating elec loop
SVT ECG
fast narrow QRS complex tachycardia
looks like QRS complex immediately followed by T wave
paroxysmal SVT
SVT reoccurs and remits in same patient over time
types of SVT: atrioventricular nodal re-enterant tachycardia
when the re-entry point is back through AV node
types of SVT: atrioventricular re-entarent tachycardia
when re-entry point is an accessory pathway (wolf-parkinson-white syndrome)
types of SVT: atrial tachycardia
electircal signal originates in atria somewhere other than SA node
acute management of stable pt w SVT
stepwise approach with cont. ECG monitoring
- valsalva maneouvre
- carotid sinus massage - massage carotid on one side w fingers
- adenosine
- alt to adenosine –> verapamil
- dirrect current cardioversion
adenosine
works by slowing cardiac conduction 1ry through AV nose
interupts AV node/accessory pathway during SVT and ‘resets’ back to sinus rhythm
how is adenosine given
as rapid bolus inot a large proximal cannula to ensure it reaches heart with enough impact to interupt pathway