title: Echocardiographic anatomy of the mitral valve in healthy dogs and dogs with myxomatous mitral valve disease.
abstract: OBJECTIVE
  To further characterize the echocardiographic anatomy of the canine mitral valve apparatus in normal dogs and in dogs affected by myxomatous mitral valve disease (MMVD).
  
  
  METHODS
  Twenty-two normal dogs and 60 dogs with MMVD were prospectively studied.
  
  
  METHODS
  The length (AMVL), width (AMVW) and area (AMVA) of the anterior mitral valve leaflet were measured in the control group and the affected group, as were the diameters of the mitral valve annulus in diastole (MVAd) and systole (MVAs). The dogs with MMVD were staged based on American College of Veterinary Internal Medicine (ACVIM) guidelines and separated into groups B1 and B2/C. All measurements were indexed to body weight based on empirically defined allometric relationships.
  
  
  RESULTS
  There was a statistically significant relationship between all log10 transformed mitral valve dimensions and body weight. The AMVL, AMVW, AMVA, MVAd and MVAs were all significantly greater in the B2/C group compared to the B1 and control groups. The AMVW was also significantly greater in the B1 group compared to the control group. Interobserver % coefficient of variation (% CV) was <10% for AMVL, AMVA, MVAd and MVAs, but was 29.6% for AMVW. Intraobserver % CV was <10.4% for all measurements.
  
  
  CONCLUSIONS
  Measurements of the anterior mitral valve leaflet and the mitral valve annulus in the dog can be indexed to body weight based on allometric relationships. Preliminary reference intervals have been proposed over a range of body sizes. Relative to normal dogs, AMVL, AMVW, AMVA, MVAd and MVAs are greater in patients with advanced MMVD.
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA. Electronic address: sonyarw@vt.edu.
authors.forename: S
authors.initials: S
authors.lastname: Wesselowski
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA.
authors.forename: M
authors.initials: M
authors.lastname: Borgarelli
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA.
authors.forename: G
authors.initials: G
authors.lastname: Menciotti
authors.affiliation: Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA 24061, USA.
authors.forename: J
authors.initials: J
authors.lastname: Abbott
mesh_terms: D000818:Animals; D049628:Body Size; D016022:Case-Control Studies; D004283:Dog Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D004285:Dogs / Q000033:anatomy & histology*; D004452:Echocardiography / Q000662:veterinary; D005260:Female; D008297:Male; D008943:Mitral Valve / Q000033:anatomy & histology*; D008945:Mitral Valve Prolapse / Q000000981:diagnostic imaging / Q000662:veterinary*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012016:Reference Values; D012720:Severity of Illness Index
keywords: Annulus; Anterior leaflet; Canine; Reference intervals