Cardiac Sympathetic Neuromodulation in the Management of Refractory Electrical Storm: A Narrative Review

Electrical storm (ES) is a life-threatening clinical condition characterized by recurrent ventricular arrhythmias within a 24 h period, carrying a high mortality rate. Despite conventional therapies, including hemodynamic optimization, antiarrhythmic drugs, implantable cardioverter-defibrillator (ICD) reprogramming, and catheter ablation, a subset of patients develop refractory ventricular arrhythmias. In this setting, cardiac sympathetic neuromodulation can interrupt arrhythmic circuits by reducing efferent sympathetic outflow to the myocardium. Stellate ganglion block (SGB) with local anaesthetic (LA) is a temporary pharmacological blockade used as rescue therapy; in the largest prospective series (the STAR study), 92% of treated patients achieved at least a 50% reduction in arrhythmic events in the 12 h following the procedure. Because the effect of anaesthetic blockade is transient, more durable interventions have been explored, including percutaneous radiofrequency or chemical neurolysis and surgical cardiac sympathetic denervation (CSD), although current evidence is largely confined to small, uncontrolled case series. This narrative review synthesizes the available evidence on cardiac sympathetic neuromodulation-spanning SGB, percutaneous neurolysis, and surgical CSD-in refractory ES, positioning these interventions primarily as a means of stabilizing patients and bridging to definitive therapy rather than as established survival-modifying treatments. Furthermore, this review describes the primary anatomical foundations of the cervicothoracic sympathetic nervous system and the various techniques for SGB, along with their most relevant clinical indications. The risks and complications associated with these interventions are also addressed. Finally, clinical implications and potential future research directions in this field are discussed, with the aim of providing guidance for the comprehensive management of critically ill patients with refractory ES.