title: Long-term follow-up on high-rate cut-off programming for implantable cardioverter defibrillators in primary prevention patients with left ventricular systolic dysfunction.
abstract: OBJECTIVE
  Implantable cardioverter defibrillators (ICDs) are efficient in reducing mortality in patients with left ventricular systolic dysfunction. High-rate cut-off programming may be effective in reducing appropriate and inappropriate therapies, but as the long-term consequences on morbidity and mortality remain unclear, it is underutilized.
  
  
  RESULTS
  We prospectively studied 365 consecutive patients (mean age 60 ± 10 years), with ischaemic (63%) or non-ischaemic cardiomyopathy and left ventricular dysfunction (mean ejection fraction 25 ± 7%), who were implanted with an ICD in primary prevention of sudden cardiac death (41% single chamber, 31% dual chamber, and 28% biventricular). All devices were programmed with a shock-only zone over 220 beats per minute (b.p.m.) and a monitoring zone between 170 and 220 b.p.m. During a median follow-up of 40 months, 41 patients received appropriate shocks (11.2%) and 24 inappropriate shocks (6.6%). Then, 306 patients never experienced any ICD shock (84%). Inappropriate discharges were related to supraventricular tachyarrhythmia in 10 patients, and noise/oversensing in 14 patients. Ventricular tachycardia episodes, sustained or not, were recorded in the monitoring zone in 43 patients (11.8%). Seven of these patients were symptomatic (1.9%), without lethal consequence. Sixty-two patients (17%) died: 35 from end-stage heart failure, 1 from unexplained sudden death, and 26 from a documented non-cardiac cause.
  
  
  CONCLUSIONS
  High-rate cut-off (220 b.p.m.) shock-only ICD programming, in primary prevention patients with reduced left ventricular ejection fraction, appeared to be safe during a long-term follow-up. It also resulted in a very low rate of discharges, which are known to be deleterious in this population.
authors.affiliation: Cardiology B Department, Service de Cardiologie B, Trousseau Hospital, François Rabelais University, 37044 Tours, France. nclementy@yahoo.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Clementy
authors.forename: Bertrand
authors.initials: B
authors.lastname: Pierre
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lallemand
authors.forename: Olivier
authors.initials: O
authors.lastname: Marie
authors.forename: Eric
authors.initials: E
authors.lastname: Lemoine
authors.forename: Pierre
authors.initials: P
authors.lastname: Cosnay
authors.forename: Laurent
authors.initials: L
authors.lastname: Fauchier
authors.forename: Dominique
authors.initials: D
authors.lastname: Babuty
mesh_terms: D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000401:mortality* / Q000517:prevention & control*