Torsade De Pointes Rx Flashcards
What is Torsades de pointes?
A specific type of polymorphic ventricular tachycardia characterized by a prolonged QT interval
What treatment may be required for persistent episodes of Torsades de pointes that result in altered mental state or haemodynamic instability?
Electrical cardioversion
What is the recommended initial magnesium dose for treating Torsades de pointes?
10 mmol IV bolus (0.05 mmol/kg in children) over 1-2 minutes
What should be done if Torsades de pointes recurs after the initial magnesium treatment?
Repeat the magnesium IV bolus
What are two alternative treatments for Torsades de pointes to increase the resting heart rate?
Isoprenaline or overdrive electrical pacing
What is the target resting heart rate for treating Torsades de pointes?
> 100 beats/min
Fill in the blank: Ensure that all QT-dependent electrolytes (potassium, magnesium, _______) are at the upper limit of normal.
calcium
Provide a magnesium treatment regimen for torsades
Load with 20mmol Magnesium over 1 hour (after initial treatment)
Start an infusion at 4mmol/hour
Magnesium target level is 1.5-2mmol/L
If Mag 2.1-2.9 = decrease infusion by 50%
Mag >3 = stop infusion and reassess in 1-2 hours
Stop after 24 hours
What symptoms/signs should be monitored while giving the magnesium infusion?
Weakness
Somnolence
Bradycardia
Dyspnoea
What delivery of magnesium should be used if eGFR <30
Intermittent bolusing instead of infusion with same targets
What observation should be normalised in Torsades?
Temperature
Hypothermia contributes to TdP
What medications should be ceased?
**QT prolonging medications
**
Antiarrhythmics:
Class IA: Quinidine, procainamide.
Class IC: Flecainide.
Class III: ibutilide, sotalol
Psychotropic:Antipsychotics e.g. haloperidol
Antibiotics: Clarithromycin/fluruoquinolones
Antifungals: Fluconazole
Other:
Methadone.
Cocaine, loperamide (when abused in massive doses).
Ondansetron (primarily when pushed rapidly).
Propofol.
Arsenic trioxide
