Ver el código de «Torsades de pointes»

==Background==
*Form of polymorphic [[VTach]]
**Gradual change in the amplitude of QRS complexes and twisting around isoelectric line
*Associated with congenital or acquired [[prolonged QT]] which may be secondary to medications

===Common Causes===
'''POINTES''' mnemonic:
*[[Phenothiazines|'''P'''henothiazines]]
*'''O'''ther medications (ie [[TCAs]])
*[[ICH|'''I'''ntracranial bleed]]
*'''N'''o known cause (idiopathic)
*'''T'''ype I [[antiarrhythmics]] ([[quinidine]], [[procainamide]], disopyramide)
*[[electrolyte Abnormality|'''E'''lectrolyte abnormalities]] ([[hypokalemia|hypoK]] & [[hypomagnesemia|hypoMg]])
*'''S'''yndrome of [[Prolonged QT]] (aka Long QT Syndrome)
*Other causes:
**[[Organophosphate toxicity]]
**[[Hydrocarbon toxicity]]
**[[Chloral hydrate toxicity]]
**[[Hypothermia]]

==Clinical Features==
*[[Syncope]]
*[[Dizziness]], lightheadedness
*[[Palpitations]]
*Sudden [[cardiac arrest]]

==Differential Diagnosis==
*Drug induced
*Congenital long QT
*[[Hypocalcemia]]
*[[Hypomagnesemia]]
*[[Hypokalemia]]
*[[Hypothermia]]
*POINTES as above

{{Tachycardia (wide) DDX}}

==Evaluation==
[[File:Torsades de Pointes (polymorphic VT).svg|thumb|Torsades de Pointes in a rhythm strip.]]
[[File:12leadTorsade.jpg|thumb|Classic torsades in 12-lead]]
[[File:Torsades de Pointes TdP.png|thumb|Torsades de Pointes (TdP) in patient with a potassium of 2.4 mmol/L and a magnesium of 1.6mg/dL.]]
===Workup===
*[[ECG]]
*BMP, Mg, Phos

===Diagnosis===
*[[ECG]] showing the QRS complexes “twisting” around the isoelectric line

==Management==
''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) drip
#**Danger of [[hypermagnesemia]] → depressed neuromuscular function and respiratory drive, so monitor closely
#**Supplement with K+
#[[Isoproterenol]] - Increases HR / AV conduction
#*2-8 mcg/min
#*Target HR > 90 bpm
#[[Overdrive Pacing]] - Atrial > Ventricular pacing
#*Goal HR 90-120
#*Note: Not a treatment for TdP, but useful in maintaining sinus rhythm
#[[Defibrillation]] / [[synchronized cardioversion]] - Patient in extremis
#'''AVOID''' amiodarone and procainamide, which may worsen prolonged QT
# [[Lidocaine]] (a class Ib antiarrhythmic drug) shortens the QT interval and may be effective especially for drug-induced torsades de pointes
#*[[Lidocaine]] 1 mg/kg bolus, followed by 0.5-4 mg/min, titrated to rhythm response<ref>Reachi B, Negrelli J, Hickman A, Beesley S, Osborn J (2019) Isoproterenol and Lidocaine for Recurrent Torsades de Pointes in a 32-year-old Pregnant Woman. Int J Crit Care Emerg Med 5:092.</ref>
#*Inpatient may monitor plasma lidocaine levels, with goal < 6 mcg/mL

==Disposition==
*Admit

==See Also==
*[[Tachycardia (Wide)]]
*[[ACLS (2010 Guidelines)]]
*[[In-Training Exam Review]]

==References==
<references/>

[[Category:Cardiology]]