Date of Graduation

Summer 8-10-2013

Degree Type

Capstone Project

Degree Name

Master of Science in Physician Assistant Studies


Background: Sudden cardiac arrest (SCA) is the leading cause of death in the United States. The implantable cardioverter defibrillator (ICD) is widely used as an adjunct therapy for SCA and has been proven to be effective in terminating life-threatening arrhythmias, but the standard transvenous device is not without complications. The development of an entirely subcutaneous ICD (S-ICD) came about as a new approach to sudden cardiac death (SCD) prevention without the lead associated complications. The S-ICD has been commercially available in Europe and New Zealand since 2009 and was recently approved by the U.S. Food and Drug Administration. The purpose of this review is to evaluate the efficacy of the new entirely subcutaneous implantable cardioverter defibrillator.

Methods: An exhaustive medical literature search was conducted using Medline-OVID, CINAHL, and Web of Science using the keywords: ‘defibrillator, implantable’ and ‘subcutaneous.’ The additional keyword ‘efficacy’ was used with Web of Science for further specification. All relevant articles were reviewed for validity and then assessed for quality using the GRADE system.

Results: Five observational cohort studies were included in this systematic review. One of the articles demonstrated a direct comparison to the TV-ICD; all others focused solely on the efficacy of the S-ICD. The studies all had similar inclusion and exclusion criteria and the patients were prognostically similar, but the quality of evidence was limited due to the observational nature. The S-ICD showed excellent intraoperative defibrillation testing and appropriate shock therapy for life-threatening arrhythmias. There were a number of inappropriate shocks delivered and complications that arose due to the novelty of the device, but many of these adverse events were completely reversible with updates to the device.

Conclusion: The entirely subcutaneous implantable cardioverter defibrillator has been demonstrated to be a reliable alternative to the standard TV-ICD in prevention of sudden cardiac death in certain populations. However, longer-term randomized controlled trials would be of great value in further defining the efficacy of this new device.

Keywords: Defibrillator, implantable; Subcutaneous; Efficacy