Subcutaneous implantable cardioverter-defibrillator: Initial experience

Abstract

Background: Implantable cardioverter-defibrillators (ICDs) are important tools in the prevention of sudden death, but implantation requires transvenous access, which is associated with complications. Subcutaneous implantable cardioverter-defibrillators (S-ICDs) may prevent some of these complications.

Aim: To evaluate the therapeutics and complications associated with S-ICD systems.

Methods: S-ICD implantation was planned in 23 patients, for whom the indications were vascular access problems, increased risk of infection or young patients with long predicted follow-up. The population consisted of four patients with ischemic heart disease, three of them on hemodialysis (two with subclavian vein thrombosis), five with left ventricular noncompaction, four with Brugada syndrome, three with arrhythmogenic right ventricular cardiomyopathy, one with transposition of the great vessels, two with dilated cardiomyopathy and four with hypertrophic cardiomyopathy.

Results: S-ICDs were implanted in 21 patients, two having failed to fulfil the initial screening criteria. Mean implantation time was 77 minutes, with no complications. Defibrillation tests were performed, and in one patient the generator had to be repositioned to obtain an acceptable threshold. In a mean follow-up of 14 months, 10 patients had S-ICD shocks, which were appropriate in half of them; one developed infection, one needed early replacement due to loss of telemetry and one patient died of noncardiac cause.

Conclusions: S-ICD implantation can be performed by cardiologists with a high success rate. Initial experience appears favorable, but further studies are needed with longer follow-up times to assess the safety and efficacy of this strategy compared to conventional devices.

Keywords: Cardioversor‐desfibrilhador implantável; Fibrilhação ventricular; Implantable cardioverter‐defibrillator; Taquicardia ventricular; Ventricular fibrillation; Ventricular tachycardia.