The EMRA Critical Care Committee's Roadblock series is the resuscitationist's guide to overcoming obstacles in the normal algorithm of critically ill patients.
Roadblock: Electrical Storm
Ventricular tachycardia (VT) or ventricular fibrillation (VF) that does not respond to standard management represents a small but serious subset of dysrhythmias collectively termed electrical storm (ES).
Common culprits of electrical storm include:
- Ischemia
- Structural heart disease
- Congenital arrhythmias
- Medications
- Toxins
- Electrolyte imbalances
- Decompensated heart failure
ACLS is an appropriate starting point for treating pulseless patients with dysrhythmia. However, the absence of universally established guidelines for the management of ES calls into consideration several questions.
At what point do we depart from the ACLS algorithm? Do we continue giving epinephrine? What other medications or interventions can we employ to address the electrical storm in these patients?
To answer some of these questions, we consulted with Rosy Thachil, MD, FACC, Assistant Professor of Medicine, Dept. of Medicine/Cardiology at Mount Sinai School of Medicine and Director of the CICU, Division of Cardiology at Elmhurst Hospital Center, and Evan Leibner, MD, PhD, Associate Professor of Emergency Medicine and Critical Care at The Mount Sinai Hospital for insight on their approach to treating patients with Electrical Storm.
How are you defining electrical storm?
Dr. Thachil: Refractory electrical storm generally refers to three or more episodes of VT/VF within a 24-hour period that do not respond to standard antiarrhythmic therapy and defibrillation efforts. The key here, though, is the persistence of of arrhythmias despite conventional treatments, (multiple doses of antiarrhythmic drugs and defibrillation attempts)
Dr. Leibner: Electrical storm is typically defined as 3 or more episodes of ventricular tachycardia or ventricular fibrillation within 24 hours. Recurrent VF is characterized by some absence of VF between episodes whereas in refractory VF, the VF is continuous throughout shocks. These are treated in the same way. A more important management branchpoint is pulse vs no pulse. If there is no pulse, then follow the ACLS pathway. If there is a pulse, focus on medical management and call ECMO early, especially in younger patients who are not responding to medical management.
Once you decide the patient is in refractory VFib, do you stop administering further epinephrine at this point or do you continue alternating epinephrine and amiodarone as indicated per ACLS protocol?
Dr. Thachil: In the case of truly refractory VFib, the ongoing use of epinephrine is controversial. While it's a cornerstone in ACLS protocols for initial VFib management, there may be diminishing returns with repeated doses in refractory cases. Continuing alternating epinephrine and amiodarone is sometimes pursued, but excessive epinephrine can also worsen myocardial oxygen consumption, potentially being counterproductive and exacerbating arrhythmia triggers in refractory cases. Many clinicians including myself, might consider discontinuing epinephrine at this point, focusing instead on medications such as amiodarone or lidocaine, and considering alternative methods like dual-sequential defibrillation. It's a case by case call.
Dr. Leibner: Once refractory VF in a pulseless patient is recognized, I would stop administering epinephrine pushes. If there is a pulse and the patient is hypotensive, I would consider a vasopressor drip - especially in the case of low diastolic pressure - to improve coronary perfusion pressure. The choice of vasopressor will depend on the clinical context (ie, patient's medical history, physical exam, etc). For example, in a young, healthy patient who is in electrical storm due to a channelopathy, I would consider phenylephrine. In an older patient with vasculopathy and a decreased ejection fraction, I would use norepinephrine because they may benefit from improved inotropy.
What other medications are you administering at this point: Lidocaine? Magnesium? Beta Blockers? Other antiarrhythmics? Sedation agents? Do you provide them in a specific order?
Dr. Thachil: In refractory VT/VF, additional pharmacologic interventions you might consider:
- Amiodarone and/or Lidocaine: Amiodarone is often first-line, but if ineffective, lidocaine may be considered as an alternative.
- Magnesium: Especially if hypomagnesemia is suspected or in the case of torsades de pointes.
- Beta-Blockers (e.g., Esmolol, Propranolol): These are increasingly used in electrical storm, especially in catecholamine-driven cases. Esmolol, for example, can help stabilize sympathetic input, and IV administration allows for rapid titration. Obviously, close hemodynamic monitoring is needed.
Dr. Leibner: In electrical storm with no pulse, follow the ACLS pathway with the first line antiarrhythmic being amiodarone. The dose I would use is amiodarone 300 mg followed by 150 mg for the second dose, and then consider an amiodarone drip at 1 mg/min. Then I would add lidocaine 100 mg followed by a lidocaine drip ranging from 1-2 mg/min. Lidocaine tends to work better for ischemic etiology of electrical storm.
In electrical storm with a pulse, for antiarrhythmics I would bolus amiodarone 150mg (as opposed to 300mg with no pulse) followed by amiodarone drip at 1 mg/min. Then I would add lidocaine as above. Shocking with synchronized cardioversion is also an option.
The next step if electrical storm continues is intubation and sedation with propofol to treat the sympathetic surge. However, avoid propofol in hypotensive shock, or use pressors such as norepinephrine or phenylephrine. I would avoid epinephrine as it would increase the sympathetic tone. Consider giving magnesium 2 mg, especially if concerned for Torsades de Pointes. Treat electrolyte derangements to maintain potassium over 4 mEq/L, phosphorus over 3 mg/dL, magnesium over 2 mg/dL, I-cal over 1.2 mmol/L.
I'm less likely to use beta blockers, but would consider esmolol if any.
Would you ever resort to a stellate ganglion block and what is its utility in the ED?
Dr. Thachil: Stellate ganglion block (SGB) is an emerging option, particularly for refractory ES with a suspected adrenergic component. The sympathetic blockade reduces cardiac excitability, providing a “neuro-modulatory” effect to reduce arrhythmias. In the ED, SGB may be challenging due to availability or expertise constraints, but if feasible, it can stabilize patients who fail traditional pharmacologic measures. I can’t say I’ve used it in the acute setting.
Dr. Leibner: No, I have not personally used this or seen this used in the EM/Crit care setting.
What is your stance on Dual Sequential Defibrillation? Has that stance changed since the publishing of DOSE VF and ReDOSE Studies?
Dr. Thachil: Dual Sequential Defibrillation (DSD) has been an area of active investigation. Just to review:
- DOSE VF: This study demonstrated some advantage to DSD (as compared to standard defibrillation) in terminating refractory VFib and survival to hospital discharge, but paucity of long term outcomes.
- ReDOSE (secondary analysis): DSD found to be the superior strategy, irrespective of whether the preceding VF was shock-refractory or recurrent.
Given these findings, I’d approach DSD as a reasonable option for certain refractory cases but with tempered expectations. The technique may improve ROSC/survival to hospital discharge in some patients. Selective rather than routine DSD probably makes sense.
Dr. Leibner: I haven't used dual sequential defibrillation. I think other options are more useful, like calling for ECMO.
If your facility has these capabilities, are you calling for ECMO cannulation in these patients if other treatment modalities fail?
Dr. Thachil: Yes, in a refractory VFib case unresponsive to medications and defibrillation attempts, ECMO/ECLS can be a life-saving bridge. ECMO provides circulatory support, allowing for organ perfusion while underlying causes are addressed or further treatment is delivered. However, ECMO initiation must be balanced with considerations of patient selection, resource availability, and the potential for meaningful neurological recovery. It’s often considered a last-resort, but in patients who meet criteria and have reversible causes (and assuming the institution is capable), ECMO offers a critical lifeline.
Dr. Leibner: In younger patients, I am very quickly getting the ECMO team involved. If the patient has a pulse, this gives you some more time. Other interventions to consider include an intra-aortic balloon pump/Impella or taking the patient for cardiac catheterization.