Criteria for an electrical storm:
(1) presence of >= 3 distinct (separated by 5 or more minutes ) episodes of sustained ventricular tachycardia and/or ventricular fibrillation
(2) within a 24 hour period
Risk factors of Arya et al for electrical storm (odds ratios from 4 to 6):
(1) width of QRS complex >= 120 milliseconds
(2) left ventricular ejection fraction < 25%.
(3) absence of beta-blocker therapy
(4) absence of ACE inhibitor therapy
The occurrence of electrical storm is an independent predictor of death (Exner et al, 2001; Verma et al, 2004).
Management may include one or more of the following (Gehi et al, 2006):
(1) Treatment of potentially reversible triggers (electrolyte imbalance, myocardial ischemia, medications that prolong the QRS interval).
(2) Administration of amiodarone or other antiarrhythmic agent, usually with beta-adrenergic blockade.
(3) Sedation with propofol.
(4) Overdrive pacing.
(5) Emergent catheter ablation (if all else fails)
