Electrical Storm in Patients With Hypertrophic Cardiomyopathy

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).

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

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

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.

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.