title: Increased cycle length variability during ventricular fibrillation: a novel predictor of arrhythmia recurrence.
abstract: To evaluate the clinical value of cycle length (CL) variability during ventricular fibrillation (VF), 26 patients who underwent implantable cardioverter defibrillator (ICD) implantation were enrolled. In VF induced for defibrillation testing, mean and SD of VFCL, mean successive differences (MSD) of VFCL, and coefficient of variations of the VFCL (CV(FF)) (SD x 100/mean VFCL) were calculated. During the follow-up period of 20 +/- 2 months, ventricular arrhythmias recurred in 13 patients. MSD and CV(FF) were 31 +/- 3(*) ms and 15.6 +/- 1.3(**) in recurrence group (n = 13), and 17 +/- 2 ms and 9.0 +/-1.1 in non-recurrence group (n = 13) ((*)P <.005, (**)P <.001 vs. nonrecurrence group). Relatively good repeatability of mean VFCL, MSD and CV(FF) in each patient was confirmed by the Bland-Altman method. In VF induced by programmed ventricular stimulation before ICD implantation, MSD and CV(FF) in recurrence group were also increased significantly. Kaplan-Meier estimates revealed that MSD >or= 20 ms and CV(FF) >or= 12 predicted higher arrhythmia recurrence (MSD, P =.039; CV(FF), P =.0069 by the log-rank test). By multivariate analysis, CV(FF) >or= 12 was a significant predictor of recurrent arrhythmic events (P =.019). In conclusion, the CL variability of VF, which was evaluated as MSD and CV(FF), is increased in patients with arrhythmia recurrence. These values may reflect the degree of electrical heterogeneity, and appears to be useful indexes of the future arrhythmic events.
authors.affiliation: Department of Cardiovascular Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Japan. yokoshh@med.hokudai.ac.jp
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yokoshiki
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Kohya
authors.forename: Minoru
authors.initials: M
authors.lastname: Sato
authors.forename: Koji
authors.initials: K
authors.lastname: Sasaki
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yotsukura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sakurai
authors.forename: Akira
authors.initials: A
authors.lastname: Kitabatake
mesh_terms: D001145:Arrhythmias, Cardiac / Q000503:physiopathology / Q000517:prevention & control; D016009:Chi-Square Distribution; D017147:Defibrillators, Implantable; D004553:Electric Conductivity; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D018754:Ventricular Dysfunction / Q000503:physiopathology*; D014693:Ventricular Fibrillation / Q000503:physiopathology* / Q000517:prevention & control*