Determination of Tricuspid Regurgitation Velocity/Pulmonary Artery Flow Velocity Time Integral in Dogs with Pulmonary Hypertension

This retrospective, echocardiographic study using 144 dogs with clear systolic tricuspid regurgitation on Doppler echocardiography was performed to determine the diagnostic value of the systolic tricuspid regurgitation velocity/pulmonary artery flow velocity time integral to predict the Doppler estimates of dogs with tricuspid regurgitation pressure gradient compared with other cardiac indices of pulmonary hypertension, and to investigate a cutoff value to select patients with a potentially poor outcome. The systolic tricuspid regurgitation velocity/pulmonary artery flow velocity time integral increased significantly as the severity of pulmonary hypertension increased and had a correlation coefficient that was analogous to those of other conventional cardiac indices. A cutoff value greater 1.65 provided the best-balanced sensitivity (84%) and specificity (80%) in determining patients with a poor prognosis. In conclusion, the systolic tricuspid regurgitation velocity/pulmonary artery flow velocity time integral is readily obtained using routine echocardiography and could provide a non-invasive, novel, and supplementary index for evaluating dogs with pulmonary hypertension as useful prognostic criteria, particularly in those with advanced pulmonary hypertension.