title: Evaluation of stability over time for measures of heart-rate variability in overtly healthy Doberman Pinschers.
abstract: OBJECTIVE
  To determine whether results of analysis of heart-rate variability (HRV) in overtly healthy Doberman Pinschers remain stable over time.
  
  
  METHODS
  24 overtly healthy client-owned Doberman Pinschers.
  
  
  METHODS
  The HRV was analyzed in time- and frequency-domains from 24-hour ambulatory electrocardiographic (Holter) monitor recordings. Activity during paired tests (tests 1 and 2) was similar (17 dogs) or nearly identical (7). Holter recordings and HRV analyses of those 17 dogs were repeated at a mean +/- SD of 65 +/- 50 weeks (median, 51 weeks; range, 10 to 177 weeks), whereas it was repeated for the other 7 dogs at 3 to 9 weeks (mean, 73 +/- 2.1 weeks).
  
  
  RESULTS
  Differences between test 1 and test 2 were not significantly different, except for 24-hour means of the normal beat-to-normal beat (NN) intervals in all 5-minute segments. Strongest correlations were for SD of all NN intervals and root mean square successive difference between adjacent NN intervals of the time-domain analyses and total power, very-low frequency power, and high-frequency power of the frequency-domain analyses. When activity during tests 1 and 2 in 7 dogs was stringently controlled, the differences were not significantly different, and correlation factors for the 24-hour HRV analyses exceeded 0.83.
  
  
  CONCLUSIONS
  Variables from sequential HRV analyses in overtly healthy Doberman Pinschers with normal echocardiograms are moderately stable when physical activity is not stringently controlled and extremely stable for at least 3 to 9 weeks when physical activity is stringently controlled.
authors.affiliation: Department of Small Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.
authors.forename: Clay A
authors.initials: CA
authors.lastname: Calvert
authors.forename: Michelle
authors.initials: M
authors.lastname: Wall
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004285:Dogs / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*