title: Beat-to-beat variability of T-wave amplitude for the risk assessment of ventricular tachyarrhythmia in patients without structural heart disease.
abstract: OBJECTIVE
  Increased temporal repolarization lability, assessed by beat-to-beat variability of T-wave amplitude (TAV), has been shown to be associated with ventricular tachyarrhythmia in patients with a variety of clinical conditions. The aim of this study was to test the ability of TAV to identify patients presenting with malignant ventricular arrhythmia and to predict subsequent occurrences.
  
  
  RESULTS
  We studied 20 consecutive patients (age 42 ± 15 years, mean ± standard deviation) presenting with ventricular tachyarrhythmia who did not have substantial underlying heart disease and compared them with 40 age- and sex-matched control subjects. The TAV was determined by Holter recording (Ela Medical). Patients with ventricular tachyarrhythmia had a higher maximum value of TAV (max TAV: 38 ± 18 vs. 22 ± 15 μV, P < 0.001) than did the controls. The sensitivity and specificity of max TAV > 22.4 μV for detecting the occurrence of ventricular tachyarrhythmia were 77 and 90%, respectively. During a mean follow-up period of 23 months, three patients had relapses of ventricular tachyarrhythmia. Patients with a recurrence of ventricular tachyarrhythmia had a trend towards a higher max TAV as compared with those who had ventricular tachyarrhythmia but did not relapse (56 ± 23 vs. 36 ± 16 μV, P = 0.061).
  
  
  CONCLUSIONS
  Our results suggest that Holter-derived TAV might be associated with the occurrence and recurrence of ventricular tachyarrhythmia in patients without structural heart disease. Prospective validation will be necessary to assess the potential diagnostic value of the TAV in a large general population.
authors.affiliation: Department of Cardiology, Fujita Health University School of Medicine, Toyoake, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sobue
authors.forename: Eiichi
authors.initials: E
authors.lastname: Watanabe
authors.forename: Mayumi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Kan
authors.initials: K
authors.lastname: Sano
authors.forename: Hiroto
authors.initials: H
authors.lastname: Harigaya
authors.forename: Kentarou
authors.initials: K
authors.lastname: Okuda
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ozaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015331:Cohort Studies; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000453:epidemiology* / Q000503:physiopathology*; D055815:Young Adult