Long-term follow-up of subcutaneous ICD systems in patients with hypertrophic cardiomyopathy: a single-center experience

• Published in: Clinical research in cardiology 2016-01, Vol.105 (1), p.89-93
• Main Authors: Frommeyer, Gerrit, Dechering, Dirk G., Zumhagen, Sven, Löher, Andreas, Köbe, Julia, Eckardt, Lars, Reinke, Florian
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Arrhythmias, Cardiac - epidemiology; Cardiology; Cardiomyopathy, Hypertrophic - physiopathology; Cardiomyopathy, Hypertrophic - therapy; Defibrillators, Implantable; Female; Follow-Up Studies; Humans; Male; Medicine; Medicine & Public Health; Middle Aged; Original Paper; Primary Prevention - methods; Prospective Studies; Registries; Secondary Prevention - methods; Time Factors; Young Adult
• ISSN: 1861-0684; 1861-0692
• DOI: 10.1007/s00392-015-0901-9

Background The totally subcutaneous implantable defibrillator (S-ICD) was introduced as a new alternative to conventional implantable defibrillators and is employed worldwide. This system is especially attractive for young patients. However, in patients with hypertrophic cardiomyopathy (HCM), T-wave oversensing may occur. To address the question whether the S-ICD system is suitable for HCM patients, the data of a standard of care prospective single-center S-ICD registry were evaluated. Methods and results In the present study, 18 HCM patients who received an S-ICD for primary ( n  = 14) or secondary prevention ( n  = 4) and a minimal follow-up duration of 6 months were analyzed. The mean follow-up duration was 31.7 ± 15.4 months. Ventricular arrhythmias were adequately detected in 4 patients (22 %). In 7 patients (39 %), T-wave oversensing was noticed and led to at least one inappropriate shock in 4 patients (22 %). Further adverse events included surgical revision due to a mobile sensing electrode and resulting noise detection as well as one case of early battery failure requiring pulse generator change. Conclusion Patients with HCM and S-ICD systems have an increased risk of T-wave oversensing and inappropriate shock delivery. Thorough monitoring as well as exercise tests may help to improve device settings and thereby prevent T-wave oversensing.