Recurrent Polymorphic VT/Torsades de Pointes - Management Algorithm

Drugs that prolong QT interval:

 • Class 1a (quinidine, disopyramide)

 • Class 1c (flecainide)

 • Class 3 (amiodarone, dofetilide, sotalol)

 • Propofol

 • Chloraquine (antimalarial)

 • Macrolides and quinolones

 • Antipsychotics (haloperidol, chlorpromazine)

 • Antidepressants (citalopram, escitalopram, amitriptyline)

 • Fluconazole, ketoconazole

 • Cocaine

 • Methadone

 • Ondansetron

 • Domperidone

 • Donepezil

Congenital long QT Syndrome

Electrolyte Abnormalities:

Hypomagnesemia

• Hypokalemia

• Hypocalcemia (rarely)

Treatment Of Recurrent TdP

First line: magnesium sulfate

  • Adult load: 2-4 gm over 10-15 minutes

  • Adult infusion after load: 0.5-1 gm/hour

  • Pediatric load: 25-50 mg/kg over 10-15 minutes

Increasing chronotropy (goal 90-110 bpm)

  • Prevents future TdP. Does NOT treat current TdP

  • Isoproterenol (non selective beta agonist)

      • Adult: 0.5-5 mcg/min

      • Pediatric: 0.1-1 mcg/min

  • Overdrive pacing (transcutaneous or transvenous)

Anti-arrhythmic

  • Class 1b (lidocaine)- case report level evidence

  • Load: 1-1.5 mg/kg

  • Infusion: I mg/min



Stacy Marshall, MD



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