Torsades de pointes: Difference between revisions
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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 | *Associated with [[prolonged QT]], which may be congenital or acquired. | ||
===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) | ||
==Clinical Features== | |||
==Diagnosis== | |||
[[File:12leadTorsade.jpg|thumb|Torsades in 12-lead]] | |||
*[[ECG] | |||
==Differential Diagnosis== | |||
==Treatment== | ==Treatment== | ||
Increasing HR decreases QT interval | Increasing HR decreases QT interval | ||
#Magnesium - decreases calcium influx | #[[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 | #**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
- [[ECG]
Differential Diagnosis
Treatment
Increasing HR decreases QT interval
- 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+
- 1-2gm IV over 1-2 min, repeat in 5-15min; then 1-2gm/hr (3-10mg/min) gtt
- Isoproterenol - Increases HR / AV conduction
- 2-8 mcg/min
- Overdrive Pacing - Atrial > Ventricular pacing
- Goal HR 90-120
- Defibrillation / Synchronized Cardioversion - Patient in extremis
See Also
Source
- Tintinalli