Management of an Electrical Storm: Definitions, Mechanisms, Diagnosis, and Treatment Strategies

An Electrical Storm (ES) is a  Ventricular Arrhythmia (VA) consisting of the occurrence of three or more Ventricular Tachycardias (VT) per day, separated by five-minute intervals, or the presence of unceasing VT, even with the optimization of antiarrhythmic  drug therapy. Data revealed that ۸۴ out of ۱۲۷۴ patients with an Implantable Cardioverter -Defibrillator (ICD) developed ES during follow-up.The incidence of ES in patients with ICD can reach ۲۰% during the first ۱۳۴ days after implantation. The pathophysiological mechanism is not well understood as ES can be caused by several clinical conditions and through several different  mechanisms, including VT and Ventricular Fibrillation (VF), global acute ischemia, and myocardial dysfunction. Patients with ES have a threefold greater risk of Sudden Cardiac Death (SCD). The  treatment is multimodal and consists primarily of emergency sedation, ventilation, neuraxial modulation, drug therapy (beta-blockers, amiodarone, sotalol, class I anti-arrhythmic drugs), and Catheter Ablation (CA). CA is a rescue procedure performed when there is little or no response to drug therapy. This approach is performed by first mapping the local and then choosing between approaches (endocardial or epicardial) and the different CA methods, which mainly include radiofrequency ablation, irrigated radiofrequency ablation, pulsed radiofrequency ablation, alcohol ablation, and cryoablation.