Difference between revisions of "Torsades de pointes"

Line 28: Line 28:
#**Danger of [[hypermagnesemia]] → depressed neuromuscular function, so monitor closely
#**Danger of [[hypermagnesemia]] → depressed neuromuscular function, so monitor closely
#**Supplement with K+
#**Supplement with K+
#Isoproterenol - Increases HR / AV conduction
#[[Isoproterenol]] - Increases HR / AV conduction
#*2-8 mcg/min
#*2-8 mcg/min
#[[Overdrive Pacing]] - Atrial > Ventricular pacing
#[[Overdrive Pacing]] - Atrial > Ventricular pacing

Revision as of 00:54, 3 June 2015


  • Torsades de Pointes is a form of polymorphic VTach, where there is a gradual change in the amplitude and twisting of the QRS complexes around the isoelectric line
  • Associated with prolonged QT, which may be congenital or acquired.

Common Causes

POINTES mnemonic:

  • Phenothiazines
  • Other medications (ie TCAs)
  • Intracranial bleed
  • No known cause (idiopathic)
  • Type I anti-arrhythmics (quinidine, procainamide, disopyramide)
  • Electrolyte abnormalities (hypoK & hypoMag)
  • Syndrome of Prolonged QT (aka Long QT Syndrome)

Clinical Features


Classic torsades in 12-lead
12-lead ECG of Torsades de Pointes (TdP) in a 56-year-old white female with a potassium of 2.4 mmol/L and a magnesium of 1.6 mg/dL.

Differential Diagnosis


Increasing HR decreases QT interval

  1. Magnesium sulfate - decreases calcium influx
    • 1-2gm IV over 1-2 min, repeat in 5-15min; then 1-2gm/hr (3-10mg/min) gtt
      • Danger of hypermagnesemia → depressed neuromuscular function, so monitor closely
      • Supplement with K+
  2. Isoproterenol - Increases HR / AV conduction
    • 2-8 mcg/min
  3. Overdrive Pacing - Atrial > Ventricular pacing
    • Goal HR 90-120
  4. Defibrillation / synchronized cardioversion - Patient in extremis

See Also