Electrical Storm Treatment by Stellate Ganglion Block

Quick Takes

  • Electrical storm (ES) is a clinical emergency with few established treatment options.
  • Percutaneous stellate ganglion block (PSGB) modulates the neuronal sympathetic activation associated with ES.
  • In patients with ES refractory to standard treatment, the STAR study suggests that PSGB is highly effective and safe when performed by trained operators.

Study Questions:

What is the effectiveness of percutaneous stellate ganglion block (PSGB) in the treatment of electrical storm (ES)?


The STAR (STellate ganglion block for Arrhythmic stoRm) study was a prospective and retrospective observational investigation conducted at multiple centers in Italy. All eligible, consecutive patients who underwent PSGB for treatment of refractory ES at a participating center between July 1, 2017–June 30, 2023 were enrolled. ES was defined as the occurrence of ≥3 discrete episodes of ventricular tachycardia (VT) or ventricular fibrillation (VF), either sustained or requiring treatment, within 24 hours. An arrhythmic event was defined as an episode of sustained VT or VF treated with either antitachycardia pacing or with a direct current shock by an internal or external defibrillator.

ES was treated by standard clinical practice at each institution, and could include management of reversible causes, antiarrhythmic drugs and beta-blockers, implantable cardioverter-defibrillator reprogramming, general anesthesia, or use of mechanical circulatory support devices. Each center could consider PSGB at any time as long as ES was refractory to other treatments. All operators were trained in the PSGB procedure at a standardized 8-hour course. The primary study outcome was the effectiveness of PSGB, defined as a ≥50% reduction in arrhythmic events during the 12 hours immediately following the PSGB procedure compared with the 12 hours immediately prior to the PSGB procedure.


The study included 131 patients from 19 centers in Italy, and 184 PSGB procedures were performed. Mean patient age was 68 years, with 83.2% males. Of all patients, most had structural heart disease, 29% had acute myocardial infarction, 21% were in cardiogenic shock, 5% were in septic shock, and 8% were in cardiac arrest. Mean left ventricular ejection fraction was 25%. Most procedures (88%) were performed on patients receiving intravenous amiodarone or lidocaine, and 3% were performed on patients receiving procainamide. Of 115 patients who suffered arrhythmic episodes requiring treatment in the 12 hours prior to PSGB, 106 (92.2%) had a reduction in the number of treated episodes of ≥50% in the 12 hours after the procedure. Thus, the primary study outcome of effectiveness of PSGB was 92.2%.

The per-patient secondary outcome of median number of treated episodes decreased from 6 per person in the 12 hours prior to PSGB to 0 per person in the 12 hours following PSGB (p < 0.001). The per-procedure secondary outcome of number of treated arrhythmic episodes in the 1 hour before versus 1 hour after each procedure decreased from 2 to 0 (p < 0.001). Only one major complication and two minor complications were observed. Time to first treated arrhythmia recurrence was longer following PSGB procedures performed with anesthetic bolus and infusion versus a single anesthetic bolus (360 minutes vs. 105 minutes, p = 0.019).


Findings from the STAR study suggest that PSGB is a highly effective and safe treatment for patients with refractory ES and support emergency use of PSGB in life-threatening situations. The study adds significantly to the evidence base for this procedure, but randomized clinical trials will be needed to establish definitive evidence.


The STAR study of 131 patients conducted in 19 centers represents the largest experience ever reported on PSGB. Previously published studies and case series of PSGB are limited in size, with only 38 patients in the largest series. The STAR study additionally assessed several previously unexamined issues, e.g., efficacy relative to anisocoria, procedural technique, low- versus high-volume centers, and timing relative to intubation. The authors suggest that current recommendations for neuromodulation might be widened.

Clinical Topics: Arrhythmias and Clinical EP, SCD/Ventricular Arrhythmias, Cardiovascular Care Team

Keywords: Sphenopalatine Ganglion Block, Tachycardia, Ventricular

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