Echocardiographic evaluation of myocardial changes observed after closure of patent ductus arteriosus in dogs.
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.


OBJECTIVES
To evaluate the short-term echocardiographic changes observed after PDA closure in dogs using strain analysis.


ANIMALS
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 AND CLINICAL IMPORTANCE
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.
['Hamabe|L|L|', 'Kim|S|S|', 'Yoshiyuki|R|R|', 'Fukayama|T|T|', 'Nakata|T M|TM|', 'Fukushima|R|R|', 'Tanaka|R|R|']
D000818:Animals D006348:Cardiac Surgical Procedures D004283:Dog Diseases D004285:Dogs D004374:Ductus Arteriosus, Patent D004452:Echocardiography D005260:Female D008297:Male D018487:Ventricular Dysfunction, Left D020257:Ventricular Remodeling
Systolic function Strain Canine Congenital heart disease