Difference between revisions of "Torsades de pointes"

(Common Causes)
Line 5: Line 5:
 
===Common Causes===
 
===Common Causes===
 
'''POINTES''' mnemonic:
 
'''POINTES''' mnemonic:
**'''P'''henothiazines
+
*'''P'''henothiazines
**'''O'''ther medications (ie TCAs)
+
*'''O'''ther medications (ie TCAs)
**'''I'''ntracranial bleed
+
*'''I'''ntracranial bleed
**'''N'''o known cause (idiopathic)
+
*'''N'''o known cause (idiopathic)
**'''T'''ype I anti-arrhythmics (quinidine, procainamide, disopyramide)
+
*'''T'''ype I anti-arrhythmics (quinidine, procainamide, disopyramide)
**'''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)
  
 
==Clinical Features==
 
==Clinical Features==

Revision as of 06:34, 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

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