First Experience With Extravascular Implantable Cardioverter-Defibrillator Under Deep Sedation

The Extravascular Implantable Cardioverter-Defibrillator (EV-ICD) utilizes a substernal lead to provide defibrillation and anti-tachycardia pacing (ATP) while avoiding transvenous complications. General anesthesia (GA) was applied for implantation procedures in the EV-ICD pivotal trial and is currently recommended by the manufacturer. However, GA carries specific risks and consumes significant resources. This study evaluates the feasibility, safety, and procedural efficiency of EV-ICD implantation performed under cardiologist-administered deep sedation with noninvasive ventilation (DS-NIV) compared to standard GA.

We retrospectively analyzed 24 consecutive patients undergoing EV-ICD implantation in our center. Patients received either GA (n = 14) or DS-NIV (n = 10) using a propofol-ketamine protocol delivered by cardiologists. Analyses focused on peri-procedural feasibility and safety, procedural workflow and anesthesia characteristics, and early device electrical performance.

No anesthesia-related complications occurred in either group. The DS-NIV group demonstrated significantly shorter wheels-to-incision times (median: 45 vs. 70 min, p = 0.022), whereas the procedural duration did not differ significantly from the GA group. Patients receiving DS-NIV required fewer vasopressors (60% vs. 100%, p = 0.024) despite higher propofol infusion rates (800 vs. 350 mg/h, P<0.001). Defibrillation testing success and electrical parameters were comparable. In a median follow-up of 182 days two patients received appropriate EV-ICD therapies and no inappropriate ATP or shocks were delivered.

EV-ICD implantation under cardiologist-administered DS-NIV appears to be feasible and safe, offering improved workflow efficiency compared to GA. These findings support deep sedation as a practical alternative in experienced centers, potentially expanding access to EV-ICD therapy.