title: Quantification of autonomic nervous activity by heart rate variability and approximate entropy in high ultrafiltration rate during hemodialysis.
abstract: BACKGROUND
  Few studies have focused on the imbalance of the autonomic nervous system in ultrafiltration rate (UFR) subjects without blood pressure variation during maintenance hemodialysis (HD), although the role of autonomic nervous system activation during HD has been proposed to be an important factor for the maintenance of blood pressure.
  
  
  METHODS
  Variations over time in autonomic nervous activity due to differences in UFR were evaluated by measuring heart rate variability (HRV) and approximate entropy (ApEn) in 35 HD patients without blood pressure variations during HD session. The subjects were divided into 3 groups, those with UFR <10 ml/h/kg; ≥10 ml/h/kg but ≤15 ml/h/kg; and >15 ml/h/kg, and Holter ECG was recorded continuously during HD session using frequency analysis of RR intervals. High frequency (HF) and low frequency (LF) spectral components are found to be representative of the parasympathetic nervous system and sympathovagal balance, respectively, with the ratio of LF to HF of HRV providing a measure of sympathetic nervous system.
  
  
  RESULTS
  In subjects with UFR >15 ml/h/kg, HF components were significantly lower, and LF/HF and ApEn values were significantly higher, in the latter half of an HD session than before starting HD.
  
  
  CONCLUSIONS
  Removing water from these subjects would promote sustained sympathetic nervous overactivity. These findings indicate that the UFR during HD needs to be set at ≤15 ml/h/kg.
authors.affiliation: Graduate School of Applied Informatics, University of Hyogo, Computational Science Center Bldg. 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan. ab13c401@ai.u-hyogo.ac.jp.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tsuji
authors.affiliation: Graduate School of Applied Informatics, University of Hyogo, Computational Science Center Bldg. 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Suzuki
authors.affiliation: Graduate School of Applied Informatics, University of Hyogo, Computational Science Center Bldg. 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Hitomi
authors.affiliation: Department of Nephrology, Yodogawa Christian Hospital, Osaka, Japan.
authors.forename: Toshiko
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Graduate School of Applied Informatics, University of Hyogo, Computational Science Center Bldg. 7-1-28 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mizuno-Matsumoto
mesh_terms: D000368:Aged; D001794:Blood Pressure; D015716:Electrocardiography, Ambulatory; D019277:Entropy; D005260:Female; D006321:Heart / Q000294:innervation*; D006339:Heart Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D014630:Vagus Nerve / Q000503:physiopathology*
keywords: Approximate entropy; Autonomic nervous activity; Heart rate variability; Sympathovagal balance; Ultrafiltration rate