title: Heart rate variability in Doberman Pinschers with and without echocardiographic evidence of dilated cardiomyopathy.
abstract: OBJECTIVE
  To characterize the salient variables of the time-domain analysis of heart rate variability (HRV) in clinically normal Doberman Pinschers and to compare those variables with those of Doberman Pinschers with cardiomyopathy and mild to moderate myocardial failure.
  
  
  METHODS
  46 Doberman Pinschers.
  
  
  METHODS
  HRV was analyzed in the time-domain from 24-hour Holter recordings obtained from 28 Doberman Pinschers with normal echocardiograms and 18 Doberman Pinschers with echocardiograms consistent with mild to moderate myocardial failure.
  
  
  RESULTS
  Significant differences in HRV variables between the 2 groups of dogs were not detected. The HRV was greater during the nighttime (12 AM to 6 AM), compared with the 24-hour day and an 18-hour (6 AM to 12 AM) period.
  
  
  CONCLUSIONS
  HRV of dogs with mild to moderate myocardial failure was not different from that of clinically normal dogs, because there were no disturbances of autonomic balance, baroreceptor function, and other factors that influence HRV in the dogs with cardiomyopathy, or the sensitivity of time-domain analysis was overwhelmed by normal sinus arrhythmia. The techniques now used to study HRV have important limitations, especially in dogs, and better noninvasive tests of autonomic function are needed.
authors.affiliation: Department of Small Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Calvert
authors.forename: G J
authors.initials: GJ
authors.lastname: Jacobs
mesh_terms: D000818:Animals; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology / Q000662:veterinary*; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs / Q000502:physiology*; D004452:Echocardiography / Q000662:veterinary; D015716:Electrocardiography, Ambulatory / Q000662:veterinary; D006339:Heart Rate / Q000502:physiology*; D016014:Linear Models; D012016:Reference Values; D012044:Regression Analysis; D012189:Retrospective Studies