title: Effect of first ventricular tachycardia cycle length on rate of ventricular arrhythmia recurrence in patients with implantable cardioverter-defibrillator.
abstract: BACKGROUND
  Some controversies exist regarding the proper treatment of hemodynamically tolerated and slow ventricular tachycardia (VT). We intended to assess the effect of cycle length of first VT episode on total ventricular arrhythmia burden in a cohort of patients with implantable cardioverter-defibrillator (ICD).
  
  
  METHODS
  Between March 2000 and March 2005, 195 patients underwent ICD implantation at our center. We included 158 patients (mean age, 58.3 +/- 12.9 years) with follow-up of 3 months or more in this study. Clinical, electrocardiographic, and ICD-stored data and electrograms were collected and analyzed.
  
  
  RESULTS
  During the follow-up of 16.7 +/- 10.6 months, 45 (28.5%) and 20 (12.6%) patients received first appropriate ICD therapy for VT and ventricular fibrillation, respectively. We divided the 45 patients with VT (based on the median value of VT cycle length) into 2 groups. Although patients with VT cycle length of less than 350 had higher total mean number of appropriate ICD therapy (25 vs 6.3, P = .023), during multivariate regression analysis, only left ventricular ejection fraction (EF) of less than 25% (P = .020) was correlated with total number of appropriate ICD therapy. First VT cycle length (P = .341), QRS duration (P = .126), age (P = .405), underlying heart disease (P = .310), indication of ICD implantation (P = .113), and sex (P = .886) have failed to predict the total burden of ventricular arrhythmia during the follow-up period.
  
  
  CONCLUSIONS
  After adjustment for left ventricular EF, initial VT cycle length per se did not confer a lower risk for subsequent ventricular arrhythmia recurrence compared with those with faster VT. Left ventricular EF of less than 25% was correlated with higher ventricular arrhythmia burden in patients with ICD.
authors.affiliation: Department of Pacemaker and Electrophysiology, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, 1996911151, Iran. dr.arasharya@gmail.com
authors.forename: Arash
authors.initials: A
authors.lastname: Arya
authors.forename: Majid
authors.initials: M
authors.lastname: Haghjoo
authors.forename: Mohammad Hosein
authors.initials: MH
authors.lastname: Nikoo
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Dehghani
authors.forename: Amir Farjam
authors.initials: AF
authors.lastname: Fazelifar
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Sadr-Ameli
mesh_terms: D015331:Cohort Studies; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D055502:Secondary Prevention; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000517:prevention & control*; D016896:Treatment Outcome