title: Heart rate variability and its changes over 5 years in older adults.
abstract: OBJECTIVE
  to characterise the association between age, ageing and heart rate variability (HRV) in older individuals, 585 adults age >65 years with two 24-h Holter recordings in the Cardiovascular Health Study were studied.
  
  
  METHODS
  heart rate (HR), ventricular premature contractions (VPCs), atrial premature contractions (APCs), frequency-domain, ratio-based and non-linear HRV and heart rate turbulence (HRT) were examined cross-sectionally by 5-year age groups and prospectively over 5 years. Analyses adjusted for gender, lower versus elevated cardiovascular (CV) risk and for the change in CV risk.
  
  
  RESULTS
  HR declined, and VPCs and APCs increased per 5-year increase in age. Frequency-domain HRV decreased more at 65-69, less at 70-74 and minimally at > or =75 years, independent of CVD risk or change in CVD risk. Ratio and non-linear HRV continued to decline to > or =75 years old. Ratio HRV and HRT slope were more strongly related to CVD risk than frequency-domain HRV.
  
  
  CONCLUSIONS
  cardiac autonomic function, assessed by frequency-domain HRV, declines most at 65-70 and levels off at age >75. The decline is independent of CVD risk or change in CVD risk. Ratio-based and non-linear HRV and HRT slope continued to change with increasing age and were more closely related to CVD risk than frequency-domain HRV.
authors.affiliation: Washington University School of Medicine, St Louis, MO, USA. pstein@im.wustl.edu
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
authors.forename: Joshua I
authors.initials: JI
authors.lastname: Barzilay
authors.forename: Paulo H M
authors.initials: PH
authors.lastname: Chaves
authors.forename: Peter P
authors.initials: PP
authors.lastname: Domitrovich
authors.forename: John S
authors.initials: JS
authors.lastname: Gottdiener
mesh_terms: D017677:Age Distribution; D000368:Aged; D000375:Aging / Q000502:physiology*; D018880:Atrial Premature Complexes / Q000453:epidemiology / Q000503:physiopathology; D001341:Autonomic Nervous System / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D017711:Nonlinear Dynamics; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D018879:Ventricular Premature Complexes / Q000453:epidemiology / Q000503:physiopathology