Clinical profile of patients undergoing percutaneous stellate ganglion block for electrical storm and association with antiarrhythmic efficacy

Background Percutaneous stellate ganglion block (PSGB) usage for patients with refractory ventricular arrhythmias (VAs) in form of electrical storm (ES) is in quickly expanding. The clinical profile of patients and the potential association with the antiarrhythmic efficacy of the procedure are mostly unexplored. Purpose To better characterize clinical profile and potential association with antiarrhythmic efficacy of patients undergoing PSGB for ES. Methods Patients undergoing PSGB for ES in our Center from 2/2021 to 2/2024 were enrolled; all the dynamic variables were evaluated in a per procedure analysis. Results 45 patients (93% male, 64 ± 10 years) received a total of 80 PSGB performed with the lateral, ultrasound (US) guided technique; most PSGB consisted of a single bolus anesthetic injection (lidocaine + ropivacaine), 26% in an additional continuous infusion, mostly with ropivacaine. All procedures except for 3 in a single patient who had previously received left cardiac sympathetic denervation, were performed on the left side. Most of the patients (60%) suffered ischemic cardiomyopathy (CMP), including 10 with an acute coronary syndrome; the rest had non-ischemic CMP; 60% had an ICD. The type of VAs was ventricular tachycardia (VTs) only in 86% of the procedures (cycle length 404 ± 143 msec), VT and VF in 10% and VF only in 3 (4%). Most PSGB (81%) were performed in the setting of impending or manifest cardiogenic shock (SCAI classification B or more), including 20% with sepsis. Cardiac US performed before (within 12 hours) each PSGB showed a severely depressed left ventricular (LV) function (mean LVEF 22 ± 10%, mean LV outflow tract velocity time integral 12 ± 4 cm), calculated at a mean heart rate of 81 ± 16 bpm. Mean LVEDV was 252 ± 104 ml, 79% had mitral regurgitation (MR) ≥2+/4+ (including 39% severe MR), 50% had ≥ moderate diastolic dysfunction, 29% had right ventricular dysfunction (mean fractional areal change 33± 7%). Most cases (75%) experienced a complete VAs suppression (sustained or treated) in the 12 hours after PSGB; only 3/80 cases required additional urgent antiarrhythmic strategies (intra-aortic ballon pump in one case, urgent pacing in another one, urgent revascularization in the last one). None of the assessed clinical or echocardiographic characteristics was significantly associated with VT cycle length or the response to PSGB. Only 1 (1%) major complication occurred (respiratory arrest), that was quickly and effectively treated with lipid emulsion. Conclusions PSGB in our Center was mostly performed in the setting of primary impending or manifest cardiogenic shock with severely impaired cardiac function, with an excellent safety profile. None of the assessed clinical or echocardiographic variables were associated with response to PSGB. Our data, despite preliminary and requiring confirmation, suggests always considering PSGB in the urgent/emergent setting independently from patients’ characteristics.