Electrical Storm in Patients With Hypertrophic Cardiomyopathy

Abstract

Background: Therapeutic strategies for electrical storm (ES) in patients with hypertrophic cardiomyopathy (HCM) are not well defined, yet this population is at risk for ventricular arrhythmias (VAs).

Objective: The aim of this study was to analyze acute management, in-hospital mortality, and long-term outcomes of patients with HCM experiencing ES.

Methods: This multicenter study retrospectively enrolled patients with ES complicating HCM between 2017 and 2023 in 6 tertiary centers.

Results: Twenty-three patients were included (mean age 61.5 ± 15.2 years, 73.9% male, left ventricular ejection fraction 50% ± 14%). Five patients (22%) had an apical aneurysm. Ten (43.4%) patients had a history of VA, including 3 with previous ES. The majority of VAs were monomorphic ventricular tachycardias (18 patients [78%]). Most patients received amiodarone (n = 20 [87%]) and beta-blockers (n = 16 [70%]). For 10 patients (44%), a radiofrequency catheter ablation was performed (including 2 endo-epicardial ablations), resulting in negative programmed ventricular stimulation in 4 patients. During their hospital management, 8 patients experienced recurrences of VA (2 [25%] previously ablated and 6 [75%] nonablated). Two (9%) patients died during the index hospitalization and 4 other patients died following discharge (median follow-up 18 months). Seven patients (30%) experienced recurrences of arrhythmias, including 4 who had undergone ablation. Radiofrequency ablation was not associated with better outcomes (recurrence rate or overall survival) in this study.

Conclusions: ES in HCM frequently resolves using antiarrhythmic drugs. Many patients will present with VA recurrences. Long-term outcomes were poor, and one-fourth of the patients ended up dying at 18 months. Further studies are warranted to better analyze radiofrequency outcomes in this specific population.

Keywords: catheter ablation; electrical storm; hypertrophic cardiomyopathy; ventricular arrhythmia.