title: Echocardiographic evaluation of myocardial changes observed after closure of patent ductus arteriosus in dogs.
abstract: BACKGROUND
  Closure of PDA can be associated with echocardiographic changes including deterioration of LV systolic function. Although PDA is commonly encountered in dogs, few comprehensive reports of echocardiographic changes in dogs with PDA closure are available.
  
  
  OBJECTIVE
  To evaluate the short-term echocardiographic changes observed after PDA closure in dogs using strain analysis.
  
  
  METHODS
  Seventeen client-owned dogs with left-to-right PDA.
  
  
  METHODS
  Echocardiographic evaluations, including standard echocardiography and two-dimensional tissue tracking (2DTT), were performed before and within 3 days of PDA closure.
  
  
  RESULTS
  Preclosure examination showed LV and left atrial dilatation indicating volume overload as a result of PDA. Closure of PDA resulted in significant reduction of LVIDd (<.0001) and LA/Ao (0.01) without change in LVIDs, suggestive of decreased preload. Postclosure LV systolic dysfunction was observed with significant decreased in FS (<.0001) and strain values (P = .0039 for radial strains, P = .0005 for circumferential strains). Additionally, significant LV dyssynchrony (P = .0162) was observed after closure of PDA.
  
  
  CONCLUSIONS
  Closure of PDA resulted in decreased preload as a result of alleviation of LV volume overload, which in turn caused transient deterioration of LV systolic function. Additionally, this study demonstrated that strain analysis is load dependent. Therefore, care should be taken when interpreting strain measurements as an indicator of LV systolic function.
authors.affiliation: Department of Veterinary Surgery, Faculty of Veterinary Medicine, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, 183-8509, Tokyo.
authors.forename: L
authors.initials: L
authors.lastname: Hamabe
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: R
authors.initials: R
authors.lastname: Yoshiyuki
authors.forename: T
authors.initials: T
authors.lastname: Fukayama
authors.forename: T M
authors.initials: TM
authors.lastname: Nakata
authors.forename: R
authors.initials: R
authors.lastname: Fukushima
authors.forename: R
authors.initials: R
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D006348:Cardiac Surgical Procedures / Q000662:veterinary*; D004283:Dog Diseases / Q000601:surgery*; D004285:Dogs; D004374:Ductus Arteriosus, Patent / Q000601:surgery / Q000662:veterinary*; D004452:Echocardiography / Q000662:veterinary*; D005260:Female; D008297:Male; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000662:veterinary*; D020257:Ventricular Remodeling
keywords: Canine; Congenital heart disease; Strain; Systolic function