Torsades de Pointes (TdP)

A type of polymorphic ventricular tachycardia that is inherently unstable and often quickly degrades into ventricular fibrillation. It usually occurs in the setting of a prolonged QT interval, which can either be genetic or acquired.


  1. Defibrillation – per ACLS, ventricular tachycardia with a pulse should receive synchronized cardioversion. But in real life, the defibrillator often isn’t able to “sync” with TdP, forcing you to perform unsynchronized cardioversion (aka defibrillation).
  2. IV Magnesium – treats and prevents TdP, even when magnesium levels are normal
  3. Overdrive Pacing – by preventing bradycardia, we help prevent TdP (bradycardia prolongs the QT interval).
    • Electrical Overdrive Pacing – transcutaneous or transvenous pacemaker
    • Chemical Overdrive Pacing – beta agonist therapy (isoproterenol)
  4. Lidocaine – anti-arrhythmic therapy that does not prolong QTc.
  5. Fix underlying cause – congenital long QT syndrome, hypokalemia, hypocalcemia, medication induced (psych meds, anti-emetics, methadone, fluoroquinolones, many more)

Defibrillation and IV Magnesium are used for patients who are ACTIVELY in TdP. Once you shock/mag them into a stable rhythm, you can use Overdrive Pacing / Lidocaine / Treat Underlying Cause to PREVENT them from going back into TdP.