Ventricular Electrical Storm - Advancing Need for Standardized Criteria and Stronger Clinical Evidence: JACC Advances

Ventricular Electrical Storm – Evolving Understanding

Ventricular electrical storm, defined by densely clustered ventricular arrhythmias (VAs), represents one of the most severe arrhythmic emergencies encountered in intensive cardiac care. Despite increased recognition and growing clinical attention, especially within cardiac and medical ICUs, ES remains a condition with limited evidence-based guidance. Most contemporary recommendations trace back to small observational studies, and the historical threshold of “three or more treated or sustained VAs in 24 hours”, widely used in guidelines, lacks robust validation. As the authors point out, ES sits at the intersection of recurrent arrhythmic instability and life-threatening acute deterioration, underscoring the need for more accurate definitions and clinically relevant risk markers.

Challenges in Ventricular Electrical Storm Research

To further highlight ongoing challenges, the authors outline methodological gaps that currently complicate ES research. Variability in defining VA events—including differences between European and American criteria regarding the requirement for events to be more than 5 minutes apart, creates heterogeneous patient populations across studies. Early trials from the 1990s included patients with two or more hemodynamically unstable VAs refractory to antiarrhythmic therapy, capturing a population with markedly higher short-term mortality than more recent cohorts. In contrast, one contemporary randomized trial comparing propranolol to metoprolol reported no deaths over 3 months, suggesting a lower-risk population. These inconsistencies limit comparability across studies and challenge the generalizability of therapeutic findings. The authors note that ES risk is influenced not only by arrhythmia burden but also by prior arrhythmic history, underlying structural disease, antiarrhythmic drug exposure, and prior ablation, factors not reflected in current definitions.

ES Therapies- Available Evidence Remains Limited in Quality and Scope

Most studies are observational, descriptive, and constrained by small sample sizes. Four randomized controlled trials have evaluated medical therapy—three from the 1990s comparing bretylium and amiodarone dosing protocols, and one from 2018 demonstrating reduced VA burden with propranolol over metoprolol when added to intravenous amiodarone. However, the clinical relevance of older trials is restricted by shifts in contemporary practice, including widespread ICD use and higher amiodarone loading strategies. Sympathetic blockade, including deep sedation with mechanical ventilation and stellate ganglion block (SGB), is supported only by observational data. Although SGB has shown reductions in VA events, the authors highlight important limitations, including the lack of comparator arms, confounding by concurrent therapies, and frequent use of blind (non-ultrasound-guided) techniques. Ongoing randomized trials—GANGSTER evaluating SGB and SEDATE assessing dexmedetomidine are expected to provide more rigorous data on the role of sympathetic modulation in acute ES management.

Way Forward for Ventricular Electrical Storm Research – Precedent Learnings from Advances in Cardiogenic Shock (CS) Care

In their final remarks, the authors underscore that meaningful progress in ES care is achievable but requires a coordinated, structured approach. They point to advances in cardiogenic shock (CS), where robust classification systems and international datasets have improved clinical research and care standardization. ES, they argue, would benefit from similar frameworks, larger multicenter networks, and collaborative efforts between electrophysiology and cardiac critical care teams. With a clear historical precedent for conducting substantial clinical trials in this population, the authors call for renewed focus and unified action to build the evidence base needed to guide clinicians managing this life-threatening arrhythmic condition.

Reference: Motazedian P, Ramirez FD, Di Santo P, Prosperi-Porta G, Nelson D, Lee JK, Jung R, Mathew R, Wells GA, Hibbert B. Lighting the Path: Advancing Research in Electrical Storm. JACC Adv. 2025 Nov 7;4(12 Pt 2):102332. doi: 10.1016/j.jacadv.2025.102332. Epub ahead of print. PMID: 41205544.