title: Multipole analysis of heart rate variability as a predictor of imminent ventricular arrhythmias in ICD patients.
abstract: BACKGROUND
  Contemporary implantable cardiac defibrillators (ICD) enable storage of multiple, preepisode R-R recordings in patients who suffered from ventricular tachyarrhythmia (VTA). Timely prediction of VTA, using heart rate variability (HRV) analysis techniques, may facilitate the implementation of preventive and therapeutic strategies.
  
  
  OBJECTIVE
  To evaluate the novel multipole method of the HRV analysis in prediction of imminent VTAs in ICD patients.
  
  
  METHODS
  We screened patients from the Biotronik HAWAI Registry (Heart Rate Analysis with Automated ICDs). A total of 28 patients from the HAWAI registries (phase I and II), having medical records, who had experienced documented, verified VTA during the 2-year follow-up, were included in our analysis. HRV during preepisode recordings of 4,500 R-R intervals were analyzed using the Dyx parameter and compared to HRV of similar length recordings from the same patients that were not followed by arrhythmia.
  
  
  RESULTS
  Our study population consisted mainly of men 25 of 28 (89%), average age of 64.8 ± 9.4 years, 92% with coronary artery disease. HRV during 64 preevent recordings (2.3 events per patient on average) was analyzed and compared with 60 control recordings. The multipole method of HRV analysis showed 50% sensitivity and 91.6% specificity for prediction of ventricular tachycardia/ventricular fibrillation in the study population, with 84.5% positive predictive value. No statistically significant correlation was found between various clinical parameters and the sensitivity of imminent VTA predetection in our patients.
  
  
  CONCLUSIONS
  The multipole method of HRV analysis emerges as a highly specific, possible predictor of imminent VTA, providing an early warning allowing to prepare for an arrhythmic episode.
authors.affiliation: Davidai Arrhythmia Center, Leviev Heart Center, Sheba Medical Center, Ramat Gan, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Rozen
authors.forename: Roi
authors.initials: R
authors.lastname: Kobo
authors.forename: Roy
authors.initials: R
authors.lastname: Beinart
authors.forename: Shlomo
authors.initials: S
authors.lastname: Feldman
authors.forename: Michal
authors.initials: M
authors.lastname: Sapunar
authors.forename: David
authors.initials: D
authors.lastname: Luria
authors.forename: Michael
authors.initials: M
authors.lastname: Eldar
authors.forename: Jacob
authors.initials: J
authors.lastname: Levitan
authors.forename: Michael
authors.initials: M
authors.lastname: Glikson
mesh_terms: D017147:Defibrillators, Implantable; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology* / Q000517:prevention & control; D016896:Treatment Outcome
keywords: ICD; heart rate variability; ventricular arrhythmia