Ver el código de «Polymorphic ventricular tachycardia»

==Background==
*Form of [[ventricular tachycardia]]
**Multiple ventricular foci
**QRS complexes with varying morphology
*Subtypes include:
**[[Torsades de pointes]]
**bidirectional polymorphic [[VTach]] (as seen in [[digoxin toxicity]])

===Etiologies===
*[[Myocardial ischemia]] (most common)
*Acquired or congenital [[prolonged QT]]
**[[TCAs]], phenothiazines, Type I antiarrhythmics (quinidine, [[procainamide]])
**[[Hypokalemia]]
**[[Hypomagnesemia]]
**[[Elevated intracranial pressure]]
*[[Brugada syndrome]], [[short QT syndrome]], congenital catecholaminergic polymorphic ventricular tachycardia

==Clinical Features==
*[[Syncope]]
*[[Palpitations]]
*[[Altered level of consciousness]]
*May present with [[cardiac arrest]]

==Differential Diagnosis==
{{Tachycardia (wide) DDX}}

==Evaluation==
[[File:Torsades de Pointes (polymorphic VT).svg|thumb|Torsades de Pointes in a rhythm strip.]]
*Evaluate for underlying causes (e.g. electrolyte imbalances, [[ACS]])

===[[ECG]] Findings===
*Wide QRS (>100ms or 3 small boxes)
*QRS complexes of varied amplitude, axis and duration
**Torsades: QRS complexes appear to twist around isoelectric line
*Rapid rhythm (usually 140-160 bpm, but can be up to 300 bpm)
*Irregular

==Management==
===Pulseless===
''See [[Adult pulseless arrest]] and [[Pediatric pulseless arrest]]
===Unstable===
*Unsynchronized cardioversion ([[defibrillation]]) 200J (or 2J/kg for pediatrics)
*Correct any electrolyte abnormalities
===Stable===
*Correct any electrolyte abnormalities
*[[Torsades]]:
**[[Magnesium]] sulfate (for Torsades): 
***1-2gm IV, repeat in 5-15min; then 1-2gm/hr (3-10mg/min) drip
***Peds: 25-50mg/kg (max 2g) IV
**[[Isoproterenol]], 2-8 mcg/min (if available)
**[[Overdrive Pacing]] to goal HR 90-120
***Note that this is only effective for preventing recurrence of TdP - it will not convert TdP to sinus rhythm
**Consider Lidocaine
**Avoid procainamide, amiodarone (may further prolong QT)
*Non-Torsades (baseline QT interval not prolonged)
**[[Amiodarone]], agent of choice in setting of AMI or LV dysfunction
***150 mg over 10min (15 mg/min), followed by 1 mg/min drip over 6hrs (360 mg total), then 0.5 mg/min drip over next 18 hrs (540 mg total)
***Peds: 5mg/kg (max 300mg), may repeat twice
**[[Procainamide]]
***100 mg q5min until termination of arrhythmia, then start 2-6 mg/min (or 1-2 mg/min for renal/cardiac failure) 
***Max dose 17mg/kg '''OR''' widening of QRS >50%
**[[Lidocaine]], 1-1.5mg/kg IV q5min, repeat PRN up to 300mg/hr
**[[Beta-blockers]] (e.g. [[metoprolol]] 5mg IV q5m x 3) if blood pressure tolerates

===Refractory===
*≥3 episodes within 24 hours considered [[electrical storm]]
*May require alternate treatment (i.e. [[β-blockers]], sedation, ablation)

==Disposition==
*Admit with cardiology consult, even if back in normal sinus rhythm
**Stable patients may be admitted to ward
***Pads should remain on patient's chest anticipating need for repeat cardioversion
***All patients should remain on telemetry or full cardio-respiratory monitoring for recurrent events
**Patients with features of instability or refractory VT are best admitted to CCU or ICU and may require urgent or emergent pacemaker placement

==See Also==
*[[Tachycardia (wide)]]
*[[Torsades de pointes]]
*[[ACLS (Main)]], [[PALS (Main)]]
*[[Adult Pulseless Arrest]], [[Pediatric pulseless arrest]]
*[[Critical care quick reference]]
*[[Nonsustained ventricular tachycardia]]

==External Links==

==References==
<references/>

[[Category:Cardiology]] [[Category:Critical Care]]