title: Rhythm-independent feature of heart rate dynamics common to atrial fibrillation and sinus rhythm in patients with paroxysmal atrial fibrillation.
abstract: OBJECTIVE
  To examine if the long-range correlation in heart rate variability is a rhythm-independent characteristic common to both atrial fibrillation (AF) and sinus rhythm (SR) periods in patients with paroxysmal atrial fibrillation (PAF).
  
  
  METHODS
  Holter electrocardiography was analyzed during sleep in 18 patients with paroxysmal atrial fibrillation during the atrial fibrillation (PAF-AF) and sinus rhythm (PAF-SR) periods, and also in 19 healthy controls with sinus rhythm (CTR-SR). The heart rate dynamics were assessed with the power-law spectral exponent (slope) of the log-log power spectrum between 0.0001 Hz and the breakpoint frequency.
  
  
  RESULTS
  The slope showed a significant correlation between PAF-SR and PAF-AF (r = 0.614, p < 0.01). During sinus rhythm, the slope in paroxysmal atrial fibrillation with cardiovascular disease [PAF-SR (cvd+)] was steeper than that in paroxysmal atrial fibrillation without cardiovascular disease [PAF-SR (cvd-)] (p < 0.05). Although the slope was comparable between PAF-SR (cvd-) and CTR-SR, the slope in PAF-SR (cvd+) was steeper than that in CTR-SR (p < 0.05). A similar tendency was shown during atrial fibrillation. The slope in paroxysmal atrial fibrillation with cardiovascular disease [PAF-AF (cvd+)] was steeper than that in paroxysmal atrial fibrillation without cardiovascular disease [PAF-AF (cvd-)] (p < 0.05). Although the slope was comparable between PAF-AF (cvd-) and CTR-SR, the slope in PAF-AF (cvd+) tended to be steeper than that in CTR-SR.
  
  
  CONCLUSIONS
  The long-range correlation in heart rate variability during sleep was a rhythm-independent characteristic and so may have a similar clinical value during atrial fibrillation and sinus rhythm in patients with paroxysmal atrial fibrillation.
authors.affiliation: Departments of Medicine and Geriatrics, Kochi Medical School, Kohasu, Oko-cho, Nankoku, Kochi 783-8505.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Sato
authors.forename: Fumiyasu
authors.initials: F
authors.lastname: Yamasaki
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuno
authors.forename: Tomio
authors.initials: T
authors.lastname: Hamada
authors.forename: Seiji
authors.initials: S
authors.lastname: Mukai
authors.forename: Junichiro
authors.initials: J
authors.lastname: Hayano
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Sugiura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Doi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation / Q000503:physiopathology*; D002940:Circadian Rhythm; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D012849:Sinoatrial Node / Q000503:physiopathology; D012890:Sleep / Q000502:physiology; D013057:Spectrum Analysis