Background: In healthy dogs, transthoracic three-dimensional echocardiography (3DE) compares more favorably with reference standard imaging and has higher reproducibility than transthoracic two-dimensional echocardiography (2DE). In dogs with cardiac disease, comparison of feasibility, efficiency, and reproducibility of left ventricular (LV) volume assessment by 3DE and 2DE has not been evaluated. Hypothesis: Both methods will be feasible and 3DE will be more efficient and reproducible than 2DE. Animals: Fifty-three dogs with cardiac disease from a university hospital.
Methods: Prospectively, all dogs underwent 2DE and 3DE examinations by three observers and 12 dogs had a second study performed on the same day. Feasibility, acquisition, and analysis time were compared using Bland-Altman and Wilcoxon signed rank test. Inter- and intraobserver variability was quantified using coefficients of variation (CV).
Results: Feasibility of 2DE and 3DE were 95% and 98% respectively. Total efficiency was 45.7% faster for 3DE (P < 0.001). Compared with 3DE, 2DE overestimates stroke volume (SV) (+3.3mL, P < 0.001) and ejection fraction (EF) (+6.1%, P < 0.001) and underestimates LV end-systolic volume (–3.5mL, P < 0.001). 3DE had lower or equivalent reproducibility than 2DE for interobserver CV (end-diastolic volume 6.4% vs. 8.7%; end-systolic volume 12.2% vs. 14.1%; SV 15.3% vs. 15.7%, EF 10.4% vs. 10.4%) and intraobserver CV (end-diastolic volume 13.6% vs. 21%; end-systolic volume 14.8% vs. 29.8%; SV 16.2% vs. 25.2%; EF 13.4% vs. 14.6%). Conclusions and clinical importance: In dogs with cardiac disease, 3DE assessment of LV volume is feasible, and more efficient and reproducible than 2DE.
