title: [Spectral analysis of systolic blood pressure in atrial fibrillation].
abstract: OBJECTIVE
  Power spectral analysis was used to analyze fluctuations of systolic blood pressure and heart rate.
  
  
  METHODS
  Non-invasive finger plethysmography and electrocardiography were performed in 20 patients with chronic atrial fibrillation and in 10 age-matched healthy subjects with normal sinus rhythm. The impulse train was stored on a personal computer and the power spectrum of R-R interval and systolic blood pressure were obtained by Fourier analysis (0.01-0.03 Hz). The power spectrum (log power vs log frequency) characteristically revealed a linear regression as 1/f beta.
  
  
  RESULTS
  The R-R interval spectrum during atrial fibrillation showed a white noise-like flat spectrum when plotted as log power against log frequency, whereas the systolic blood pressure spectrum during atrial fibrillation showed a 1/f noise-like negative slope linear pattern. The spectrum exponent of systolic blood pressure in patients with atrial fibrillation was significantly lower than that in subjects with normal sinus rhythm (2.3 +/- 0.1 vs 1.3 +/- 0.1, p < 0.0001).
  
  
  CONCLUSIONS
  Systolic blood pressure fluctuation in patients with atrial fibrillation has a fractal component and is more complex than that of healthy subjects with normal sinus rhythm.
authors.affiliation: Department of Radiology, Cardiovascular Institute Hospital, Roppongi 7-3-10, Minato-ku, Tokyo 106-0032.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Arai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.forename: Machiko
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Hajime
authors.initials: H
authors.lastname: Kirigaya
authors.forename: Tadanori
authors.initials: T
authors.lastname: Aizawa
authors.forename: Long-Tai
authors.initials: LT
authors.lastname: Fu
mesh_terms: D001281:Atrial Fibrillation / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology*; D004562:Electrocardiography; D005260:Female; D005583:Fourier Analysis; D017709:Fractals; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D013599:Systole