title: Heart rate, heart rate variability, and arrhythmias in dogs with myxomatous mitral valve disease.
abstract: BACKGROUND
  Autonomic modulation of heart rhythm is thought to influence the pathophysiology of myxomatous mitral valve disease (MMVD).
  
  
  OBJECTIVE
  (1) Holter-derived variables reflecting autonomic modulation of heart rhythm change with MMVD severity in Cavalier King Charles Spaniels (CKCS); (2) Holter-derived variables can identify MMVD severity in CKCS; and (3) Holter-derived variables in CKCS in congestive heart failure (CHF) secondary to MMVD differ from those in dogs of other breeds in CHF.
  
  
  METHODS
  Ninety privately owned dogs: 70 CKCS with variable MMVD severity and 20 non-CKCS in CHF secondary to MMVD.
  
  
  METHODS
  Dogs were prospectively recruited and divided into 5 MMVD severity groups based on history, breed, and physical and echocardiographic examination findings. Holter-derived variables included heart rate variability (HRV), heart rate (HR), and arrhythmia evaluated from 24-hour Holter recordings.
  
  
  RESULTS
  In CKCS, 18 of 26 HRV (all P < .0002) and 3 of 9 arrhythmia (all P < .0004) variables decreased with increasing MMVD, whereas minimum and mean HR (all P < .0001) increased with increasing MMVD severity. An arrhythmia variable representing sinus arrhythmia ("premature normals") (P < .0001) and the HRV variable triangular index (TI) (P < .0001) could distinguish CKCS with moderate or severe mitral regurgitation from CKCS in CHF in specific intervals. Among dogs in CHF, Holter-derived variables did not differ among breeds.
  
  
  CONCLUSIONS
  In CKCS, Holter-derived variables changed with MMVD severity. "Premature normals" and TI showed diagnostic potential. Breed differences were not seen among dogs in CHF secondary to MMVD.
authors.affiliation: Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Frederiksberg, Denmark. cer@life.ku.dk
authors.forename: C E
authors.initials: CE
authors.lastname: Rasmussen
authors.forename: T
authors.initials: T
authors.lastname: Falk
authors.forename: N E
authors.initials: NE
authors.lastname: Zois
authors.forename: S G
authors.initials: SG
authors.lastname: Moesgaard
authors.forename: J
authors.initials: J
authors.lastname: Häggström
authors.forename: H D
authors.initials: HD
authors.lastname: Pedersen
authors.forename: B
authors.initials: B
authors.lastname: Ablad
authors.forename: H Y
authors.initials: HY
authors.lastname: Nilsen
authors.forename: L H
authors.initials: LH
authors.lastname: Olsen
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004285:Dogs; D015716:Electrocardiography, Ambulatory / Q000662:veterinary; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D006339:Heart Rate / Q000502:physiology; D006349:Heart Valve Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000662:veterinary*; D008297:Male; D008943:Mitral Valve / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D014463:Ultrasonography