Practical tricks for Percutaneous Stellate Ganglion Block (PSGB) in patients with electrical storm

Background Percutaneous Stellate Ganglion Block (PSGB) is gaining traction for the treatment of patients with Electrical Storm (ES) but little is known on how to increase its effectiveness. Purpose We sought to evaluate whether the number of local anaesthetics used and the heart rhythm at the moment of PSGB could affect the effectiveness of the procedure. Methods We considered the PSGBs performed from 1st July 2017 to 30th April 2024 at the 19 Centres of the STAR group. The number of arrhythmias treated with shock (internal or external) or with anti-tachycardia pacing (ATP) 1h before and 1h after each procedure was compared, according to the number of anaesthetics (single or combined) used and the rhythm at the moment of the procedure: sinus, ventricular tachycardia (VT) or ventricular fibrillation (VF). Logistic regression models were used to test the association of the number of anaesthetics used and the type of rhythm with the probability of complete suppression of arrhythmias in the first hour after the procedure. Results We considered 254 PSGBs: 77 (30%) performed with a single anaesthetic (65 lidocaine, 8 bupivacaine, 3 mepivacaine and 1 ropivacaine); 174 (68%) with a combination of two local anaesthetics (68 lidocaine+bupivacaine, 94 lidocaine+ropivacaine and 12 lidocaine+mepivacaine); in 3 cases the anaesthetic was unknown. At the moment of PSGB the rhythm was sinus in 100 (40%) procedures, VT in 87 (34%), VF in 32 (13%); 33 (13%) PSGBs were performed during other rhythm (2 unknown cases). A significant reduction in treated arrhythmias was documented in the first hour after the block both with one single anaesthetic and two in combination [one: 5 (2-8) vs 0 (0-1), p<0.01; combination: 1 (0-5) vs 0 (0-0), p<0.01]. A significant reduction was highlighted also for all the rhythms at the moment of the procedure [sinus: 1 (0-4) vs 0 (0-0), p<0.01); VT: 3 (0-7) vs 0 (0-0), p<0.01); VF: 3 (5-9) vs 1 (0-3), p<0.01)]. The combination of two anaesthetics [OR 5.4 (2.6-10.9),p<0.01] and the presence of sinus rhythm at the moment of PSGB [OR 3.8 (1.6-8.9),p<0.01] were associated with the probability of complete suppression of arrhythmias. After correction for tachycardia cycle, number of intravenous antiarrhythmic drugs used and number of arrhythmias treated in the previous hour, only the use of two anaesthetic drugs was significantly associated with the probability of having complete suppression of arrhythmias in the following hour [OR 4.4 (1.7-11.8), p<0.01]. Conclusions PSGB was effective regardless the number of anaesthetics and the type of rhythm. However, the combination of a rapid onset anaesthetic drug and a long-acting one resulted independently associated to the probability of complete arrhythmic suppression.