title: Long-term follow-up of subcutaneous ICD systems in patients with hypertrophic cardiomyopathy: a single-center experience.
abstract: 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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany. Gerrit.Frommeyer@ukmuenster.de.
authors.forename: Gerrit
authors.initials: G
authors.lastname: Frommeyer
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany.
authors.forename: Dirk G
authors.initials: DG
authors.lastname: Dechering
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Zumhagen
authors.affiliation: Division of Cardiac Surgery, Department of Cardiothoracic Surgery, University of Münster, Münster, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Löher
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Köbe
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Eckardt
authors.affiliation: Division of Electrophysiology, Department of Cardiovascular Medicine, University of Münster, Münster, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Reinke
mesh_terms: D000293:Adolescent; D000328:Adult; D001145:Arrhythmias, Cardiac / Q000453:epidemiology*; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology / Q000628:therapy*; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000379:methods; D011446:Prospective Studies; D012042:Registries; D055502:Secondary Prevention / Q000379:methods; D013997:Time Factors; D055815:Young Adult
keywords: Device complications; Hypertrophic cardiomyopathy; S-ICD; Sudden cardiac death; T-wave oversensing