Definition
The occurrence of three or more hemodynamically stable ventricular tachyarrhythmias within 24 hours
VT recurring soon after (within five minutes) termination of another VT episode
Sustained and non-sustained VT resulting in a total number of ventricular ectopic beats greater than sinus beats in a 24-hour period
In patients with an ICD, the most widely accepted definition of electrical storm is three or more appropriate therapies for ventricular tachyarrhythmias, including antitachycardia pacing or shocks, within 24 hours
Pathophysiology
VT/VF increases intracellular calcium levels, which may be pro-arrhythmic.
Shocks and episodes of cardiac arrest (e.g. treated with epinephrine) may cause myocardial injury.
Myocardial injury and pain stimulate an outpouring of endogenous catecholamines, promoting recurrent arrhythmia.
Medical antiarrhythmic therapy
Amiodarone (1st line)
300 mg bolus (over 10 minutes), then 1 mg/min x6 hours, then 0.5 mg/min.
Additional boluses can be given for recurrence (up to a total of ~900 mg in boluses).
Avoid >2.2 grams total dose within 24 hours (i.e., >900 mg in bolus doses).
Patients on chronic oral amiodarone should still be reloaded with IV amiodarone
propranolol (2nd line)
Loading bolus 0.15 mg/kg IV over 10 minutes (~10 mg). Follow heart rate and hold the infusion if the heart rate falls <45 b/m.
Maintenance: 3-5 mg IV Q6hr.
OR
esmolol infusion (2nd line)
Loading dose is 0.5 mg/kg IV (~30 mg) over one minute.
Start infusion at 0.050 mg/kg/min (~3 mg/min).
May re-load & up-titrate infusion in increments of 0.05 mg/kg/min every 10 minutes, up to a maximal dose of 0.3 mg/kg/min (~20 mg/min).
Lidocaine (3rd line)
Bolus with 1-1.5 mg/kg and then infuse at a rate of 0.02 mg/kg/min (~1.5 mg/min)
May re-bolus with 0.5-0.75 mg/kg IV, up to a total dose of 3 mg/kg.
May titrate up to ~4 mg/min.
modestly effective in scar-related monomorphic VT, but it may be more useful in the context of acute ischemia
Consider Reversible Triggers
Drug toxicity
Electrolyte disturbances (ie, hypokalemia and hypomagnesemia)
New or worsened heart failure
Acute myocardial ischemia
Thyrotoxicosis
QT prolongation (which may be related to drug toxicity, electrolyte imbalance, or an underlying syndrome such as long QT syndrome)
Intubation and sedation
Intubation is often required for a true VT storm as patients may lose airway control during episodes of VT/VF
Deep sedation itself is therapeutic.
Propofol seems to work particularly well here but may cause hypotension due to vasodilation
Dexmedetomidine may also reduce sympathetic tone, however, has some drawbacks which make it 2nd line
Dexmedetomidine is sluggish to titrate.
Dexmedetomidine can't achieve the same depth of deep sedation that propofol can.
Benzodiazepine may be used if the patient is unable to tolerate propofol/dexmedetomidine due to severe hypotension.
Analgesia is important for any intubated patient, but it's especially important in VT storm because untreated pain can drive sympathetic tone and promote recurrent arrhythmia.
Management of refractory cases
Catheter ablation
Thoracic epidural anesthesia and/or general anesthesia
Insertion of an intraaortic balloon pump or a temporary ventricular assist device
Stellate ganglion block
References
Farkas, J. (2023, March 21). Monomorphic VT storm. EMCrit Project. https://emcrit.org/ibcc/storm/#definition
Passman, R. (n.d.). Electrical storm and incessant ventricular tachycardia. UpToDate. https://www.uptodate.com/contents/electrical-storm-and-incessant-ventricular-tachycardia
Drew Nguyen, MD
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