title: Predictors and Proarrhythmic Consequences of Inappropriate Implantable Cardioverter-Defibrillator Therapy.
abstract: BACKGROUND
  Despite the benefits of implantable cardioverter-defibrillator (ICD) therapy, inappropriate shocks can lead to multiple adverse effects. The aim of this study was to clarify the predictors of inappropriate ICD shocks and their proarrhythmic consequences.
  
  
  RESULTS
  We retrospectively studied 316 consecutive patients who underwent ICD implantation from December 2000 to December 2011. Of them, 70 (22%) experienced inappropriate ICD shocks without proarrhythmia requiring some intervention; 2 patients (0.6%) had proarrhythmic inappropriate ICD therapy by antitachycardia pacing (ATP), thereby calculated to be 0.18% of patients per year. However, they did not have syncope from this inappropriate ATP. Multivariate analysis identified younger age (≤56 years: hazard ratio [HR] 1.68, 95% confidence interval [CI] 1.02-2.77, P=0.043), paroxysmal atrial fibrillation (HR 3.00, 95% CI 1.64-5.31, P=0.0002), stroke (HR 2.23, 95% CI 1.11-4.47, P=0.024), and no diuretic use (HR 1.72, 95% CI 1.03-2.93, P=0.039) as independent predictors of the occurrence of inappropriate ICD shocks.
  
  
  CONCLUSIONS
  Young age, paroxysmal atrial fibrillation, stroke, and no use of diuretics were independently associated with inappropriate ICD shocks. Proarrhythmic inappropriate ICD therapy was observed with an annual incidence of 0.18% by ATP.
authors.affiliation: Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine.
authors.forename: Taro
authors.initials: T
authors.lastname: Tenma
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yokoshiki
authors.forename: Kazuya
authors.initials: K
authors.lastname: Mizukami
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Mitsuyama
authors.forename: Masaya
authors.initials: M
authors.lastname: Watanabe
authors.forename: Ryo
authors.initials: R
authors.lastname: Sasaki
authors.forename: Motoki
authors.initials: M
authors.lastname: Maeno
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Matsui
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsutsui
mesh_terms: D001281:Atrial Fibrillation / Q000401:mortality* / Q000628:therapy*; D017147:Defibrillators, Implantable / Q000009:adverse effects*; D018572:Disease-Free Survival; D004554:Electric Countershock / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D020521:Stroke / Q000209:etiology / Q000401:mortality*; D015996:Survival Rate