The evaluation and management of electrical storm

Abstract

Electrical storm is an increasingly common and life-threatening syndrome that is defined by 3 or more sustained episodes of ventricular tachycardia, ventricular fibrillation, or appropriate shocks from an implantable cardioverter-defibrillator within 24 hours. The clinical presentation can be dramatic. Electrical storm can manifest itself during acute myocardial infarction and in patients who have structural heart disease, an implantable cardioverter-defibrillator, or an inherited arrhythmic syndrome. The presence or absence of structural heart disease and the electrocardiographic morphology of the presenting arrhythmia can provide important diagnostic clues into the mechanism of electrical storm. Electrical storm typically has a poor outcome.The effective management of electrical storm requires an understanding of arrhythmia mechanisms, therapeutic options, device programming, and indications for radiofrequency catheter ablation. Initial management involves determining and correcting the underlying ischemia, electrolyte imbalances, or other causative factors. Amiodarone and β-blockers, especially propranolol, effectively resolve arrhythmias in most patients. Nonpharmacologic treatment, including radiofrequency ablation, can control electrical storm in drug-refractory patients. Patients who have implantable cardioverter-defibrillators can present with multiple shocks and may require drug therapy and device reprogramming. After the acute phase of electrical storm, the treatment focus should shift toward maximizing heart-failure therapy, performing revascularization, and preventing subsequent ventricular arrhythmias. Herein, we present an organized approach for effectively evaluating and managing electrical storm.

Keywords: Anti-arrhythmiaagents/therapeutic use; cardiomyopathies/complications; catheter ablation; death, sudden, cardiac/prevention & control; defibrillators, implantable/adverse effects; electrocardiogra-phy; heart arrest/etiology/therapy; myocardial infarction/complications; risk factors; tachycardia, ventricular/complications/drug therapy/physiopathology/therapy; ventricular fibrillation/complications/diagnosis/drug therapy/physiopathology/therapy.

Fig. 1 Management of electrical storm. ACLS = advanced cardiac life support; ECG = electrocardiographic; EP = electrophysiology; IABP = intra-aortic balloon pump; ICD =implantable cardioverter-defibrillator; LSGB = left stellate ganglion blockade; PVC = premature ventricular contraction; Revasc = revascularization; VF = ventricular fibrillation; VT = ventricular tachycardia

Fig. 2 Treatment of multiple implantable cardioverter-defibrillator (ICD) shocks. AF = atrial fibrillation; ATP = antitachycardia pacing; EP = electrophysiology; IABP = intra-aortic balloon pump; SVT = supraventricular tachycardia; VF = ventricular fibrillation; VT = ventricular tachycardia