title: Effects of stroke on changes in heart rate variability during hemodialysis.
abstract: BACKGROUND
  Stroke and low heart rate variability (HRV) are both associated with an unfavorable prognosis in hemodialysis patients. The relationship between stroke and changes in HRV during hemodialysis remains unclear.
  
  
  METHODS
  This study measured differences between predialysis and postdialysis HRV (△HRV) in 182 maintenance hemodialysis patients, including 30 patients with stroke, to assess changes in HRV during hemodialysis, and also to compare results to 114 healthy controls.
  
  
  RESULTS
  All predialysis HRV measurements had no differences between stroke patients and those without stroke, but were lower than healthy controls. Postdialysis very low frequency (VLF) (P < 0.001), low frequency (LF) (P = 0.001), total power (TP) (P < 0.001) and the LF/high frequency (HF) ratio (P < 0.001) increased significantly relative to predialysis values in patients without stroke, whereas postdialysis HRV did not increase in stroke patients. After multivariate adjustment, dialysis vintage was negatively associated with △VLF (β = -0.698, P = 0.046), △LF (β = -0.931, P = 0.009), and △TP (β = -0.887, P = 0.012) in patients without stroke. Serum intact parathyroid hormone (β = -0.707, P = 0.019) was negatively associated with △LF. Total cholesterol (β = -0.008, P = 0.001) and high sensitivity C-reactive protein (β = -0.474, P = 0.012) were inversely correlated with the △LF/HF ratio in patients without stroke.
  
  
  CONCLUSIONS
  HRV in hemodialysis patients is lower than in the general population. Increase in △HRV was observed in hemodialysis patients without stroke but not in stroke patients. This result suggests suppressed autonomic nervous reactions against volume unloading during hemodialysis, which might contribute to unfavorable outcomes in hemodialysis patients but even more so in those with prior stroke. Nephrologists should notice the importance of △HRV especially in high-risk patients.
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Jiun-Chi
authors.identifier: http://orcid.org/0000-0002-5897-2860
authors.initials: JC
authors.lastname: Huang
authors.affiliation: Division of Neurology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Chien-Fu
authors.initials: CF
authors.lastname: Chen
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Changhua Christian Hospital, 135 Nanxiao Street, Changhua City, 500, Taiwan.|School of Medicine, Chung Shan Medical University, Taichung, Taiwan.|Program for Aging, China Medical University, Taichung, Taiwan.
authors.forename: Chia-Chu
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.|Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Szu-Chia
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan.|Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Hsieh
authors.affiliation: Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan. 102407@cch.org.tw.|Division of Nephrology, Department of Internal Medicine, Changhua Christian Hospital, 135 Nanxiao Street, Changhua City, 500, Taiwan. 102407@cch.org.tw.|School of Medicine, Chung Shan Medical University, Taichung, Taiwan. 102407@cch.org.tw.
authors.forename: Yao-Peng
authors.initials: YP
authors.lastname: Hsieh
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.|Faculty of Renal Care, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Hung-Chun
authors.initials: HC
authors.lastname: Chen
mesh_terms: D005260:Female; D006339:Heart Rate; D000070276:Heart Rate Determination / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology* / Q000628:therapy*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000503:physiopathology*
keywords: Autonomic nervous system; Heart rate variability; Hemodialysis; Stroke