title: The use of signal analyses of ventricular tachycardia electrograms to predict the response of antitachycardia pacing in patients with implantable cardioverter-defibrillators.
abstract: BACKGROUND
  Antitachycardia pacing (ATP), a quick, painless, and effective therapy available in implantable cardioverter-defibrillators (ICDs), can terminate most, but not all, sustained ventricular tachycardias (VTs). This study investigated the possible ventricular electrogram (EGM) factors for predicting the effectiveness of ATP therapy from ICD recordings.
  
  
  RESULTS
  In this study, we analyzed 113 EGMs of VT episodes acquired from 20 patients who received ATP or shock to terminate tachyarrhythmias during follow-up after ICD implantations. The relationship between the outcome of ATP and VT EGM features (such as voltage, width, cycle length, and beat-to-beat morphologic variation) was investigated. The divergence (beat-to-beat morphologic variation) of the VT EGMs was determined by calculating the total deviation of all EGMs away from the average template after all VT EMGs were aligned. In total, 72 (63.7%) successful (Group I) and 41 (36.3%) unsuccessful (Group II) ATP therapy episodes were analyzed. The mean amplitude, cycle length, and EGM width were similar between these 2 groups (P > 0.05). A multivariate analysis demonstrated that the only predictor of successful ATP was the divergence among the VT EGMs (0.56 ± 0.32 vs 1.07 ± 0.64, P < 0.001, for Groups 1 and 2, respectively). The optimal cutoff value for determining a successful ATP therapy was 0.73 (with an area under the curve of 0.769, sensitivity of 81.9% [95% CI = 71.1-90.0], and specificity of 65.9% [95% CI = 49.4-79.9], P < 0.0001).
  
  
  CONCLUSIONS
  Signal analyses from stored EGMs of VT can predict the response of ATP therapy in patients with ICD implantations. A lesser ventricular beat-to-beat morphologic variation in the intracardiac recordings from ICDs correlated with a higher probability of a successful ATP.
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.|Division of Cardiology, Taipei Municipal Gan-Dau Hospital, Taipei, Taiwan.
authors: Ta-Chuan
authors: TC
authors: Tuan
authors: Research Center for Adaptive Data Analysis, Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Jhongli, Taiwan, R.O.C.
authors: Men-Tzung
authors: MT
authors: Lo
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
authors: Yenn-Jiang
authors: YJ
authors: Lin
authors: Research Center for Adaptive Data Analysis, Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Jhongli, Taiwan, R.O.C.|Medical Biodynamics Program, Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors: Wan-Hsin
authors: WH
authors: Hsieh
authors: Research Center for Adaptive Data Analysis, Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Jhongli, Taiwan, R.O.C.|Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Palo Alto, California, USA.
authors: Chen
authors: C
authors: Lin
authors: Research Center for Adaptive Data Analysis, Analysis and Center for Dynamical Biomarkers and Translational Medicine, National Central University, Jhongli, Taiwan, R.O.C.
authors: Norden E
authors: NE
authors: Huang
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
authors: Li-Wei
authors: LW
authors: Lo
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
authors: Tze-Fan
authors: TF
authors: Chao
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
authors: Jo-Nan
authors: JN
authors: Liao
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan.
authors: Yu-Cheng
authors: YC
authors: Hsieh
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan.
authors: Tsu-Juey
authors: TJ
authors: Wu
authors: Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Faculty of Medicine and Institute of Clinical Medicine, National Yang-Ming University, School of Medicine, Taipei, Taiwan.
authors: Shih-Ann
authors: SA
authors: Chen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015331:Cohort Studies; D017147:Defibrillators, Implantable; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D017180:Tachycardia, Ventricular / Q000503:physiopathology* / Q000628:therapy*
keywords: antitachycardia pacing; electrogram; implantable cardioverter-defibrillator; signal analysis; ventricular tachycardia