Electrical storm treated with radiation therapy in a patient with ischaemic cardiomyopathy and left ventricular thrombus: a case report.

Background: Electrical storm in patients with structural heart disease is associated with high morbidity and mortality. Catheter ablation is recommended for drug-refractory ventricular tachycardia (VT), but may be contraindicated in the presence of a left ventricular (LV) thrombus due to increased thromboembolic risk. Stereotactic arrhythmia radiotherapy (STAR) has emerged as a non-invasive treatment option for refractory VT. This case highlights the potential role of STAR as a rescue therapy when conventional approaches are not feasible. Case summary: An 80-year-old man with advanced ischaemic cardiomyopathy presented after out-of-hospital cardiac arrest due to monomorphic VT. Evaluation revealed severe LV dysfunction (LVEF 15%), an anteroapical LV aneurysm and a newly detected LV thrombus. Catheter ablation was deferred due to embolic risk. Eleven weeks later, the patient was admitted with recurrent VT and developed electrical storm refractory to antiarrhythmic drug therapy, overdrive pacing, and bilateral stellate ganglion blockade. Non-invasive target delineation using contrast-enhanced cardiac computed tomography with scar characterization and ECG-based localization was performed. A single fraction of 25 Gy stereotactic arrhythmia radiotherapy was delivered to the suspected VT substrate. Electrical storm terminated immediately after treatment, and no further VT episodes occurred during hospitalization or during 6 months of follow-up. Discussion: This case demonstrates that stereotactic arrhythmia radiotherapy may provide an effective non-invasive rescue strategy for electrical storm when catheter ablation is contraindicated. Integration of advanced cardiac imaging with ECG-based localization enables target definition in the absence of invasive electroanatomical mapping.