Difference between revisions of "Torsades de pointes"

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==Background==
 
==Background==
 
*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
 
*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. '''POINTES''' mnemonic for common etiologies:
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*Associated with [[prolonged QT]], which may be congenital or acquired.  
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===Common Causes===
 +
'''POINTES''' mnemonic:
 
**'''P'''henothiazines
 
**'''P'''henothiazines
 
**'''O'''ther medications (ie TCAs)
 
**'''O'''ther medications (ie TCAs)
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**'''E'''lectrolyte abnormalities (hypoK & hypoMag)
 
**'''E'''lectrolyte abnormalities (hypoK & hypoMag)
 
**'''S'''yndrome of Prolonged QT (aka Long QT Syndrome)
 
**'''S'''yndrome of Prolonged QT (aka Long QT Syndrome)
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 +
==Clinical Features==
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 +
==Diagnosis==
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[[File:12leadTorsade.jpg|thumb|Torsades in 12-lead]]
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*[[ECG]
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==Differential Diagnosis==
  
 
==Treatment==
 
==Treatment==
 
Increasing HR decreases QT interval
 
Increasing HR decreases QT interval
#Magnesium - decreases calcium influx
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#[[Magnesium sulfate]] - decreases calcium influx
 
#*1-2gm IV over 1-2 min, repeat in 5-15min; then 1-2gm/hr (3-10mg/min) gtt
 
#*1-2gm IV over 1-2 min, repeat in 5-15min; then 1-2gm/hr (3-10mg/min) gtt
#**Danger of hyperMag2+ → depressed neuromuscular function, so monitor closely
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#**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

Revision as of 06:33, 25 February 2015

Background

  • 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

Diagnosis

Torsades in 12-lead
  • [[ECG]

Differential Diagnosis

Treatment

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

Source

  • Tintinalli