Electrical Storm and ICD Therapy: An Overview Update

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. The objective of this chapter is to promote an overview update of electrical storm in patients with ICD Therapy. Data revealed that 84 out of 1274 patients with an implantable cardioverter-defibrillator (ICD) developed ES during follow-up. The incidence of ES in patients with ICD can reach 20% during the first 134 days after implantation. The pathophysiological mechanism is not well understood, because 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.