An entirely subcutaneous implantable cardioverter–defibrillator

Bardy, G.H. et al. (2010) An entirely subcutaneous implantable cardioverter–defibrillator. New England Journal of Medicine, 363(1), pp. 36-44. (doi: 10.1056/NEJMoa0909545)

Abstract

BACKGROUND Implantable cardioverter–defibrillators (ICDs) prevent sudden death from cardiac causes in selected patients but require the use of transvenous lead systems. To eliminate the need for venous access, we designed and tested an entirely subcutaneous ICD system.

METHODS First, we conducted two short-term clinical trials to identify a suitable device configuration and assess energy requirements. We evaluated four subcutaneous ICD configurations in 78 patients who were candidates for ICD implantation and subsequently tested the best configuration in 49 additional patients to determine the subcutaneous defibrillation threshold in comparison with that of the standard transvenous ICD. Then we evaluated the long-term use of subcutaneous ICDs in a pilot study, involving 6 patients, which was followed by a trial involving 55 patients.

RESULTS The best device configuration consisted of a parasternal electrode and a left lateral thoracic pulse generator. This configuration was as effective as a transvenous ICD for terminating induced ventricular fibrillation, albeit with a significantly higher mean (±SD) energy requirement (36.6±19.8 J vs. 11.1±8.5 J). Among patients who received a permanent subcutaneous ICD, ventricular fibrillation was successfully detected in 100% of 137 induced episodes. Induced ventricular fibrillation was converted twice in 58 of 59 patients (98%) with the delivery of 65-J shocks in two consecutive tests. Clinically significant adverse events included two pocket infections and four lead revisions. After a mean of 10±1 months, the device had successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia.

CONCLUSIONS In small, nonrandomized studies, an entirely subcutaneous ICD consistently detected and converted ventricular fibrillation induced during electrophysiological testing. The device also successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia.

• Item Type: Articles
• Additional Information: From New England Journal of Medicine, Bardy, G.H., Smith, W.M., Hood, M.A., Crozier, I.G., Melton, I.C., Jordaens, Luc, Theuns, D., Park, R.E., Wright, D.J., Connelly, D.T., Fynn, S.P., Murgatroyd, F.D., Sperzel, J., Neuzner, J., Spitzer, S.G., Ardashev, A.V., Oduro, A., Boersma, L., Maass, A.H., Van Gelder, I.C., Wilde, A.A., van Dessel, P.F., Knops, R.E., Barr, C.S., Lupo, P., Cappato, R., and Grace, A.A. , An entirely subcutaneous implantable cardioverter–defibrillator, 363:1, 36-44. Copyright © 2010 Massachusetts Medical Society. Reprinted with permission
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Connelly, Dr Derek
• Authors: Bardy, G.H., Smith, W.M., Hood, M.A., Crozier, I.G., Melton, I.C., Jordaens, L., Theuns, D., Park, R.E., Wright, D.J., Connelly, D.T., Fynn, S.P., Murgatroyd, F.D., Sperzel, J., Neuzner, J., Spitzer, S.G., Ardashev, A.V., Oduro, A., Boersma, L., Maass, A.H., Van Gelder, I.C., Wilde, A.A., van Dessel, P.F., Knops, R.E., Barr, C.S., Lupo, P., Cappato, R., and Grace, A.A.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: New England Journal of Medicine
• Publisher: Massachusetts Medical Society
• ISSN: 0028-4793
• ISSN (Online): 1533-4406
• Copyright Holders: Copyright © 2010 Massachusetts Medical Society
• First Published: First published in New England Journal of Medicine 363(1):36-44
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher