title: Reliability of heart rate variability in healthy older women at rest and during orthostatic testing.
abstract: OBJECTIVE
  In the older population, the reliability of heart rate variability (HRV) has only been evaluated in a few studies, in the supine position, and covering a broad sample of age and patients of both sexes. To document the relevance of using HRV analysis in healthy older women, the aim of this study was to evaluate the reliability of HRV indexes during three classical tests.
  
  
  METHODS
  33 healthy women (66.9+/-0.7 years old) performed two test sessions. Each session consisted of an ECG recorded in the supine position, first with free breathing (Test 1), then with controlled breathing (Test 2), and in the upright position (Test 3). Time and frequency HRV indexes were obtained by processing the ECG signals. Reliability was assessed between sessions using Student's paired t-test, intraclass correlation coefficient (ICC) and coefficient of variation (CV).
  
  
  RESULTS
  There were no differences between the sessions. ICC showed good reliability for all HRV indexes. CV was low for absolute HRV indexes, except in Test 3 for parasympathetic indexes with modest CV. The CV of HRV ratio indexes were modest to high in all three tests.
  
  
  CONCLUSIONS
  Time and absolute frequency HRV indexes are reliable when testing healthy older women. Our results support the use of such indexes in gerontology research, to assess the effects of clinical or pharmacological interventions on the autonomic nervous system.
authors.affiliation: Groupe de Recherche Cardiovasculaire, Université de Rennes 1, Rennes cedex, France sylvia_reland@yahoo.fr
authors.forename: Sylvia
authors.initials: S
authors.lastname: Reland
authors.forename: Nathalie S
authors.initials: NS
authors.lastname: Ville
authors.forename: Sara
authors.initials: S
authors.lastname: Wong
authors.forename: Guy
authors.initials: G
authors.lastname: Carrault
authors.forename: François
authors.initials: F
authors.lastname: Carré
mesh_terms: D000368:Aged; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015203:Reproducibility of Results