Evaluation of right ventricular regional volume and systolic function in healthy Beagle dogs using real-time three-dimensional echocardiography (RT3DE)

Objective: To evaluate the value of real-time three-dimensional echocardiography (RT3DE) in the assessment of right ventricular (RV) regional volume and systolic function, and to explore the characteristics of RT3DE parameters in healthy canine model. Methods: RT3DE images were acquired from 10 healthy Beagle dogs for evaluation and analysis to obtain RV global and regional end-diastolic volume (EDV), end-systolic volume (ESV), systolic volume (SV) and ejection fraction (EF) in three compartments (inflow, body and outflow). Time to minimum systolic volume (Tmsv) and Tmsv corrected by heart rate (Tmsv%) in three RV compartments were calculated. Conventional echocardiographic parameters including RV diameters and left ventricular stroke volume were calculated and recorded. Results: It was found that EDV, ESV and SV in the inflow compartment were the highest in the three compartments of the right ventricle of healthy Beagle dogs (all P<0.05). The differences among regional EF, Tmsv and Tmsv% were not significant. RV global EDV was positively correlated with RV end-diastolic diameters and area (all P<0.05). RV global ESV was positively correlated with RV end-systolic diameters and area (all P<0.05). There was no significant difference between RV global SV and left ventricular stroke volume. RV global EF and EF in the inflow compartment were positively correlated with RV fractional area change (P<0.05). Intra-observer and test-retest variability of RT3DE parameters was relatively low with high consistency. Conclusions: In healthy Beagle dogs, there were distinct characters of regional volume and high systolic synchronicity in the three compartments of the right ventricle. RT3DE may play a potential role in the evaluation of RV regional volume and systolic function.