title: Depressed cardiac autonomic modulation in patients with chronic kidney disease.
abstract: BACKGROUND
  A dysfunctional autonomic nervous system (ANS) has also been recognized as an important mechanism contributing to the poor outcome in CKD patients, with several studies reporting a reduction in heart rate variability (HRV).
  
  
  OBJECTIVE
  Evaluate the sympathovagal balance in patients with chronic kidney disease on conservative treatment.
  
  
  METHODS
  In a cross-sectional study, patients with CKD stages 3, 4 and 5 not yet on dialysis (CKD group) and age-matched healthy subjects (CON group) underwent continuous heart rate recording during two twenty-minute periods in the supine position (pre-inclined), followed by passive postural inclination at 70° (inclined period). Power spectral analysis of the heart rate variability was used to assess the normalized low frequency (LFnu), indicative of sympathetic activity, and the normalized high frequency (HFnu), indicative of parasympathetic activity. The LFnu/HFnu ratio represented sympathovagal balance.
  
  
  RESULTS
  After tilting, CKD patients had lower sympathetic activity, higher parasympathetic activity, and lower sympathovagal balance than patients in the CON group. Compared to patients in stage 3, patients in stage 5 had a lower LFnu/HFnu ratio, suggesting a more pronounced impairment of sympathovagal balance as the disease progresses.
  
  
  CONCLUSIONS
  CKD patients not yet on dialysis have reduced HRV, indicating cardiac autonomic dysfunction early in the course of CKD.
authors: School of Medical and Health Sciences of Juiz de Fora.
authors: Carlos Alberto
authors: CA
authors: de Oliveira
authors: Medical School, University of São Paulo.
authors: Helio Lima
authors: HL
authors: de Brito Junior
authors: Federal University of Juiz de Fora.
authors: Marcus Gomes
authors: MG
authors: Bastos
authors: Dante Pazzanese Institute of Cardiology.
authors: Felipe Gomes
authors: FG
authors: de Oliveira
authors: Federal University of Minas Gerais.
authors: Thais Gomes
authors: TG
authors: Casali
authors: Dante Pazzanese Institute of Cardiology.
authors: Tiago Costa
authors: TC
authors: Bignoto
authors: Federal University of Juiz de Fora.
authors: Natalia Maria da Silva
authors: NM
authors: Fernandes
authors: Federal University of Juiz de Fora.
authors: Antonio Fernando de Castro Alves
authors: AF
authors: Beraldo
authors: Federal University of Juiz de Fora.
authors: Rogério Baumgratz
authors: RB
authors: de Paula
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D006321:Heart / Q000294:innervation* / Q000503:physiopathology*; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000503:physiopathology*