title: Pathologic Manifestations on Surgical Biopsy and Their Correlation with Clinical Indices in Dogs with Degenerative Mitral Valve Disease.
abstract: BACKGROUND
  Evaluation of myocardial function is clinically challenging in dogs with degenerative mitral valve disease (DMVD). Although myocardial dysfunction is caused by pathologic degeneration, histopathologic progression is poorly understood.
  
  
  OBJECTIVE
  To characterize myocardial and pulmonary pathologic changes according to severity in dogs with naturally occurring DMVD, and to investigate whether or not pathologic degeneration is reflected by traditional clinical indices.
  
  
  METHODS
  One hundred and seventeen dogs with naturally occurring DMVD.
  
  
  METHODS
  Prospective observational study. Biopsied left atrium (LA), left ventricle (LV), and lung were evaluated histologically, and an attempt was made to correlate pathologic findings with clinical indices.
  
  
  RESULTS
  Severe myocardial changes were observed in all International Small Animal Cardiac Health Council classes. In the lung, heart failure cell levels were significantly increased in class III patients (P < .0001). In a paired comparison, the LA showed significantly more severe degeneration than the LV, including myocardial fatty replacement, immune cell infiltration, and interstitial fibrosis (P < .0001). In contrast, myocardial cells were more hypertrophied in the LV than in the LA (P < .0001). Left ventricular end-diastolic dimension (LVEDd) was associated with fatty replacement (P = .033, R(2) = 0.584) and myocardial vacuolization (P = .003, R(2) = 0.588) in the LA.
  
  
  CONCLUSIONS
  In DMVD, although severe pathologic changes may be evident even in early stages, there may be pathologic discrepancy between the LA and the LV. Myocardial degeneration may be reflected by clinical indices such as LVEDd and EF.
authors.affiliation: Veterinary Cardiovascular Medicine and Surgery Unit, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.affiliation: Veterinary Cardiovascular Medicine and Surgery Unit, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.|Japan Animal Specialty Medical Institute Inc., JASMINE Veterinary Cardiovascular Medical Center, Yokohama, Kanagawa, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Mizuno
authors.affiliation: Veterinary Cardiovascular Medicine and Surgery Unit, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.|Japan Animal Specialty Medical Institute Inc., JASMINE Veterinary Cardiovascular Medical Center, Yokohama, Kanagawa, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mizuno
authors.affiliation: Veterinary Cardiovascular Medicine and Surgery Unit, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.|Japan Animal Specialty Medical Institute Inc., JASMINE Veterinary Cardiovascular Medical Center, Yokohama, Kanagawa, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Harada
authors.affiliation: Veterinary Cardiovascular Medicine and Surgery Unit, Department of Veterinary Medicine, College of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa, Japan.|Japan Animal Specialty Medical Institute Inc., JASMINE Veterinary Cardiovascular Medical Center, Yokohama, Kanagawa, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Uechi
mesh_terms: D000818:Animals; D001706:Biopsy / Q000662:veterinary; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology*; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D005260:Female; D006325:Heart Atria / Q000473:pathology; D006352:Heart Ventricles / Q000473:pathology; D008168:Lung / Q000473:pathology; D008297:Male; D008943:Mitral Valve / Q000473:pathology; D008944:Mitral Valve Insufficiency / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D011446:Prospective Studies; D012720:Severity of Illness Index
keywords: Heart failure; Mitral regurgitation; Myocardial degeneration; Myocardial fibrosis