Defibrillation success with a second generation intercostal extravascular ICD lead and commercially available left pectoral pulse generator

Abstract Background/Introduction An investigational intercostal extravascular ICD lead has been developed for compatibility with commercially available pulse generators (PGs) that are placed in a left pectoral position in appropriate patients. This is substantially different from currently available extravascular ICD systems that require a custom PG placed in a left lateral position. Purpose The purpose of this analysis was to evaluate sensing and defibrillation of a second-generation intercostal, extravascular defibrillation lead (EV-ICD Lead) when used with currently available ICD PGs in a traditional left pectoral location. Methods Patients (n=20) undergoing an ICD implant or replacement underwent acute VF EV-ICD Lead connected to a left pectoral pulse generator. Induced VF was sensed and shocked using a 10 J safety margin, with subsequent higher-energy shocks delivered if required. Testing was also conducted in the left lateral pocket for a paired analysis with patients serving as their own control. Results Automatic sensing of acute, induced VF episodes from the left pectoral PG was successful in 19 of 20 patients (95%) whose pre-induction R-waves were greater than 1.0 mV and unsuccessful in one subject with a pre-induction R-wave of 0.3 mV. VF was successfully terminated with a 10 J safety margin in 17 of 20 (83%) patients, a 5 J safety margin in 2 of 20 (10%) patients and failed to convert one patient (BMI 32.9) from the pectoral pocket (however, conversion was successful from a lateral pocket with a 10 J shock, which provides a 30 J safety margin. With a left lateral ICD, 100% of patients demonstrated successful VF termination with ≥10 J safety margin. Conclusion(s) Sensing and defibrillation using a left pectoral PG location is feasible with a new intercostal, extravascular defibrillation lead.