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

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.

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.

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.

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.

Sensing and defibrillation using a left pectoral PG location is feasible with a new intercostal, extravascular defibrillation lead.