Skip to main content
Echocardiographic assessment of right ventricular systolic function in conscious healthy dogs following a single dose of pimobendan versus atenolol.
Published Web Locationhttps://doi.org/10.1016/j.jvc.2015.04.001
ObjectiveTo quantify drug-induced changes in right ventricular (RV) systolic function after administration of pimobendan and atenolol.
Animals80 healthy privately-owned dogs.
MethodsUsing a prospective, blinded, fully-crossed study design with randomized drug administration, RV systolic function was determined twice at two time periods; before and 3 h after administration of pimobendan (0.25 mg/kg PO) or atenolol (1 mg/kg PO). Indices of RV systolic function included tricuspid annular plane systolic excursion (TAPSE), fractional area change (FAC), pulsed-wave tissue Doppler-derived systolic myocardial velocity of the lateral tricuspid annulus (S'), and speckle-tracking-derived global longitudinal RV free wall strain and strain rate. The effect of treatment on percent change from baseline RV function was analyzed with a linear mixed model including the covariates heart rate, body weight, age, gender, drug sequence, and time period.
ResultsAll indices showed a significant (p < 0.0001) increase and decrease from baseline following pimobendan and atenolol, respectively. Significant differences from baseline were attributed to drug treatment (p < 0.0001); whereas, effects of other covariates were not significant. The greatest percent changes, but also highest variability, were observed for S' and strain rate (p < 0.0001). Post-atenolol, a significantly greater proportion of dogs exceeded the repeatability coefficient of variation for FAC and S' compared to TAPSE (p ≤ 0.007).
ConclusionsEchocardiographic indices in healthy dogs tracked expected changes in RV systolic function following pimobendan and atenolol and warrant study in dogs with cardiovascular disease.
For improved accessibility of PDF content, download the file to your device.