Efficacy of early use of percutaneous stellate ganglion block for electrical storms

Background: Electrical Storm (ES) is a life-threatening condition requiring a rapid management. Percutaneous Stellate Ganglion Block (PSGB) proved to be safe and effective on top of standard therapy, but no data are available about its early use. Methods: We considered all patients enrolled from 1st July 2017 to 30th April 2024 in the STAR registry (STellate ganglion block for Arrhythmic stoRm), a multicentre, international, observational, prospective registry. We aimed to assess the effectiveness of the first PSGB only. Patients were divided into two groups depending on whether they received PSGB before (Early-PSGB, often due to AAD contraindication) or after (Delayed-PSGB) intravenous antiarrhythmic drugs (AADs other than beta-blockers). Results: We considered 180 PSGB (26 Early-PSGB and 154 AAD-first). In the early-PSGB group we observed a statistically significant reduction of treated arrhythmic events in the hour after PSGB compared to the hour before: 0 (0-0) vs 4.5 (1-10), p<0.001 and the extent of the reduction was similar in the Early-PSGB and delayed-PSGB group [-4.5 (-7 to -2) vs. -2.5 (-3.5 to -1.5), p=ns]. The percentage of patients free from arrhythmias was similar in the two groups up to 12 hours after PSGB (81%vs 84%, p=0.6 after one hour; 77% vs 79%, p=0.8 at three hours and 65% vs 69%, p= 0.7 after 12 hours). Conclusions: PSGB proved to be effective also when used early in the treatment of ES. Due to its rapidity of action, our results may suggest its early use to reduce the number of defibrillations and possibly to reduce the likelihood of a refractory ES.