Arrhythmias Flashcards
What are the 4 cardiac arrest rhythms?
Ventricular tachycardia
Ventricular fibrillation
Pulseless electrical activity (all electrical activity except VF/VT, including sinus rhythm without a pulse)
Asystole (no significant electrical activity)
Which cardiac arrest rhythms are shockable?
VT
VF
Which cardiac arrest rhythms are not shockable
Pulseless electrical activity (all electrical activity except VF/VT, including sinus rhythm without a pulse)
Asystole (no significant electrical activity)
Tachycardia treatment in an unstable patient
Up to 3 synchronised shocks
Amiodarone infusion
Narrow complex tachycardias
AF- rate or rhythm control
Atrial flutter- BB
Superventricular tachycardias- vagal manoeuvres and adenosine
Broad complex tachycardias
Ventricular tachycardia- amiodarone
Atrial flutter- what is it and how do we treat
It is a re-entrant rhythm in either atrium forming a self-perpetuating loop
Atrial contraction at 300bpm. ventricular contraction at 150bpm
Saw tooth appearance
Rate/rhythm control w BBs or direct current cardioversion
How can we treat recurrent atrial flutter?
Radiofrequency ablation of the tricuspid valve isthmus is curative for most patients
Supraventricular Tachycardias (SVT) what is it?
Re-entry from ventricles up to atria
SVT Mx
Valsalva manoeuvre- blow hard against resistance
Carotid sinus massage
Adenosine (or verapamil)
Direct current cardio version if other options fail
Adenosine MOA and method of administration in SVT
Slows conduction through AV node and rests sinus rhythm
Rapid bolus
Causes brief period of asystole or bradycardia
Key points to remember about adenosine: cautions and how to administer
Avoid in asthma/COPD/ heart failure/ heart block/ severe hypotension
Warn about feeling of impending doom
Give as fast IV bolus into antecubital fossa
Initially 6mg, then 12mg then a further 12 mg if no improvement between doses
Long Term Management of patients with paroxysmal SVT
BBs
Ca channel blockers
Amiodarone
Radiofrequency ablation
Wolff-Parkinson White Syndrome- what is it and how do we notice on ECG?
Extra pathway connecting atria and ventricles (Bundle of Kent)
Short PR
Wide QRS
Delta wave- slurred upstroke on QRS complex
Wolff-Parkinson White Syndrome definitive treatment
Radiofrequency ablation of accessory pathway
What is radiofrequncy ablation?
Catheter up femoral vein
Wire through venous system under X-ray guidance to heart
The ablate the abnormal area of electrical activity
Torasdes de pointes- what is it and how do we notice on ECG?
Polymoprhic ventricular tachycardia
Height of QRS get smaller and smaller then larger then smaller etc
Prolonged QT due to prolonged repolarisation
This results in random spontaneous depolarisation in some areas known as afterdepolarisations which lead to ventricular contraction before proper depolarisation
What are the 2 outcomes of torsades de pointes
Terminate and revert to sinus
Progress to VT
Causes of prolonged QT
Long QT syndrome (inherited)
Medications- antipsychotics, citalopram, flecainide, stall, amiodarone, macrolide ABx
Electrolyte disturbance- hypOkalaemia, hypOmagnesaemia, hypOcalcaemia
Mx Torsades
Correct cause eg meds or electrolyte
Mg infusion even if normal Mg
Defib if –> VT
Long term mx of prolonged QT syndrome
Avoid danger meds
Correct electrolytes
BB (not sotalol)
Pacemaker or implantable defibrillator
How do we manage unstable patients w VT?
Immediate cardioversion
or without pulse
Defib
How do we manage stable patients w VT?
Amiodarone
Lidocaine- unless LV impariment
Procainamide
1st degree heart block
Delayed conduction through AV node
PR> 0.2 seconds (5small squares or 1 big)
