title: Implantable cardioverter-defibrillators in patients with hypertrophic cardiomyopathy -- dilemmas and difficulties.
abstract: BACKGROUND
  The implantation of a cardioverter-defibrillator (ICD) is an established method of sudden cardiac death (SCD) prevention. The value of ICD therapy in secondary prevention of SCD is unquestionable. Precise identification of high-risk patients and ICD use for primary prevention of SCD, especially in patients with hypertrophic cardiomyopathy (HCM), remain controversial. Problems include the high prevalence of complications associated with ICD implantation and optimal selection of ICDs.
  
  
  OBJECTIVE
  To estimate the frequency and type of complications after ICD implantations in HCM patients in a long-term follow-up.
  
  
  METHODS
  The efficacy and safety of ICD therapy were estimated in 46 HCM patients with devices implanted for a secondary (n-18) or primary prevention (n-28) of SCD.
  
  
  RESULTS
  During the mean follow-up period of 28.2+/-26.1 months (from 2 to 68) appropriate ICD interventions occurred in 10 (55%) patients of the secondary prevention group and in 3 (10%) patients of the primary prevention group. Complications were documented in 15 (33%) patients. The most frequent were inappropriate ICD interventions recorded in 14 (30%) patients. The causes of these inappropriate ICD shocks were: T-wave oversensing (7 patients), atrial fibrillation with rapid ventricular rhythm (3 patients), lead failure (2 patients), and sinus tachycardia (2 patients). In two patients infections of the ICD pocket requiring removal of the system occurred. Displacement of the lead occurred in one patient. There were no significant differences in the prevalence of complications between the primary and secondary prevention groups or in the number of inappropriate interventions with respect to ICD type.
  
  
  CONCLUSIONS
  The high rate of appropriate ICD shocks provides proof of high ICD-based SCD prevention efficacy. There is a high rate of complications observed after ICD implantation with inappropriate interventions being the most frequent among them. This indicates that careful programming of the device as well as the use of a programme with T-wave oversensing prevention should be ensured.
authors.affiliation: 2nd Coronary Department, Institute of Cardiology, Warsaw, Poland. aprzybylski@ikard.pl
authors.forename: Andrzej
authors.initials: A
authors.lastname: Przybylski
authors.forename: Longina
authors.initials: L
authors.lastname: Małecka
authors.forename: Mariusz
authors.initials: M
authors.lastname: Pytkowski
authors.forename: Lidia
authors.initials: L
authors.lastname: Chojnowska
authors.forename: Michał
authors.initials: M
authors.lastname: Lewandowski
authors.forename: Maciej
authors.initials: M
authors.lastname: Sterliński
authors.forename: Aleksander
authors.initials: A
authors.lastname: Maciag
authors.forename: Witold
authors.initials: W
authors.lastname: Ruzyłło
authors.forename: Hanna
authors.initials: H
authors.lastname: Szwed
mesh_terms: D000328:Adult; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000628:therapy*; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D015716:Electrocardiography, Ambulatory; D019544:Equipment Failure Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000517:prevention & control; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000209:etiology / Q000517:prevention & control