11. Peri-arrest arrhythmias Flashcards
What are life-threatening features associated with arrhythmias?
- Shock
- Syncope
- Heart failure
- Myocardial ischaemia
- Extremes of heart rate
What is the algorithm for managing tachycardia?
What defibrillator energies should be used during synchronised cardioversions for different forms of arrhythmias?
- Broad-complex tachycardia - 120-150J
- AF - Maximum defibrillator output
- Narrow-complex tachycardia/atrial flutter - 70-120J
What treatments should be given to treat regular broad-complex tachycardias?
- Amiodarone 300mg IV over 10-60mins followed by 900mg IV over 24hrs
- If still persisting, consider synchronised cardioversion
How should Torsade de Pointes VT be treated?
- Magnesium sulfate 2g IV over 10mins
- Correct underlying electrolye imbalance
- Synchronised cardioversion if any adverse features
What are the requirements relating to cardioversion in AF?
- In general, patients in AF for >48hrs requiring cardioversion needs to be anticoagulated for at least 3 weeks unless:
1. TTO echo shows absence of atrial thrombus
2. Therapeutic LMWH or unfractionated heparin bolus followed by infusion of unfractionated heparin to maintain APTT of 1.5-2, then commence anticoagulation therapy soon after cardioversion
What drugs may be used for chemical cardioversion of AF?
- Propafenone
- Flecainide
- Amiodarone - If above contraindicated, though less effective
What is the algorithm for managing bradycardia?
Which patients should not be given atropine for treatment of bradycardia?
Cardiac transplant patients, as their heart is denervated so will not respond to vagal blockade and may cause paradoxical sinus arrest
In which patients should alernative second-line drugs be considered over atropine in bradycardia?
- Glucagon if beta-blocker/calcium-channel blocker toxicity suspected
- Digoxin-specific antibodies if digoxin toxicity suspected
- Aminophylline if bradycardia complicated by acute anterior-inferior wall infarct, spinal cord injury or cardiac transplantation
