Right ventricular systolic function in dogs with pulmonary hypertension can be assessed using tissue motion annular...

To assess right ventricular (RV) systolic function using conventional echocardiography and advanced techniques, including strain and tissue motion annular displacement (TMAD), in dogs with and without pulmonary hypertension (PH).

Dogs with PH and healthy client-owned dogs (control group) evaluated from March 2018 through June 2022 were eligible for inclusion in this case-control study. Dogs in the PH group were classified as having either precapillary or postcapillary PH. All dogs underwent physical examination, blood pressure measurement, electrocardiography, and echocardiographic evaluation, including conventional and speckle-tracking techniques. Right ventricular systolic function was assessed using multiple variables, including TMAD, measured as midpoint displacement (millimeters), midpoint displacement relative to RV length (percentage), and TMAD indexed to body weight (mm/kg) and body surface area (mm/m2). The results were compared among groups and subgroups.

There were 46 dogs in the PH group (precapillary PH, n = 27; postcapillary PH, 19) and 44 dogs in the control group. The TMAD values were lowest in dogs with precapillary PH compared with the control group and dogs with postcapillary PH. Tissue motion annular displacement (mm/kg) showed weak to moderate positive correlations with RV structural variables and fractional area change percentage, a weak negative correlation with tricuspid annular plane systolic excursion normalized by body weight, and no significant correlation with peak velocity of systolic tricuspid annular motion as determined by tissue Doppler imaging (S').

TMAD does not replace conventional techniques for assessing RV systolic function.

The evaluated technique may serve as a supplementary tool for assessing RV systolic function in dogs with PH.