title: Frequency analysis of signal-averaged electrocardiogram in patients with right ventricular tachycardia.
abstract: OBJECTIVE
  The purpose of this study was to analyze the frequency content of signal-averaged electrocardiograms (ECGs) in patients with idiopathic ventricular tachycardia of right ventricular origin and in patients with arrhythmogenic right ventricular dysplasia.
  
  
  BACKGROUND
  The late potentials in the time domains are usually found in patients with arrhythmogenic right ventricular dysplasia. They are not usually found in patients with idiopathic ventricular tachycardia of right ventricular origin.
  
  
  METHODS
  Fast Fourier transform analysis of signal-averaged ECGs was performed with the use of a Blackman-Harris window in 43 subjects: 20 normal volunteers (group I), 12 patients with idiopathic ventricular tachycardia of right ventricular origin (group II) and 11 patients with arrhythmogenic right ventricular dysplasia (group III), and the frequency spectrum was displayed in a three-dimensional graph. Area ratio (ratio of the area under the spectral plot from 40 to 120 Hz to the area from 0 to 120 Hz) was calculated in all subjects.
  
  
  RESULTS
  Area ratio was significantly higher in group II than in group I (243 +/- 45 vs. 196 +/- 15, p < 0.01) and significantly higher in group III (396 +/- 51) than in group I or II (p < 0.001). The high frequency components in group II were confined within the QRS complex in the three-dimensional graph, whereas those in group III extended outside the QRS complex.
  
  
  CONCLUSIONS
  Frequency analysis of the signal-averaged ECG with fast Fourier transform analysis can detect the high frequency components in patients with right ventricular tachycardia, including idiopathic ventricular tachycardia and arrhythmogenic right ventricular dysplasia.
authors.affiliation: Division of Cardiology, National Cardiovascular Center, Osaka, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Kinoshita
authors.forename: S
authors.initials: S
authors.lastname: Kamakura
authors.forename: T
authors.initials: T
authors.lastname: Ohe
authors.forename: N
authors.initials: N
authors.lastname: Aihara
authors.forename: H
authors.initials: H
authors.lastname: Takaki
authors.forename: T
authors.initials: T
authors.lastname: Kurita
authors.forename: C
authors.initials: C
authors.lastname: Yutani
authors.forename: K
authors.initials: K
authors.lastname: Shimomura
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001706:Biopsy; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D006328:Cardiac Catheterization; D002304:Cardiac Pacing, Artificial / Q000379:methods / Q000706:statistics & numerical data; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods* / Q000706:statistics & numerical data; D004594:Electrophysiology; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology