Systolic function in dogs with pulmonic stenosis of different severities and the effect of balloon valvuloplasty

Introduction/objectives: Pulmonic stenosis (PS) is one of the most com-mon congenital heart diseases in dogs leading to right ventricular (RV) pressure overload, myocardial remodeling, and potential RV dysfunction. Our objectives were to investigate the extent of RV systolic dysfunction in canine PS and to exam-ine the immediate influence of balloon valvuloplasty (BV) on systolic function.Animals, materials and methods: This prospective study evaluated 72 dogs with PS and 86 healthy dogs. Echocardiographic parameters of systolic function included normalized tricuspid annular plane systolic excursion (N-TAPSE), normalized systo-lic myocardial tissue Doppler velocity of the lateral tricuspid annulus (N-RVFW-S'), fractional area change, and speckle-tracking longitudinal endocardial RV strain. Forty-four dogs underwent BV and were re-examined after surgery.Results: Systolic function at the basal segment of the RV was significantly lower in the PS group when compared to healthy dogs (mean N-TAPSE 4.29 +/- standard de-viation 1.18 mm/kg0.285 vs. 5.60 +/- 1.29 mm/kg0.285; median N-RVFW-S' 5.28 [lower-upper 25% quantile 4.35-6.43 cm/s/kg0.186] vs. 7.82 [6.73-8.7 9 cm/s/ kg0.186]; all P<0.001). Global longitudinal RV endocardial strain showed no signifi-cant difference between the two groups (-28.50 +/- 6.23% vs. 28.61 +/- 4.64%; P=0.886), but segmental strain analyses revealed basal hypo-and potential com-pensatory hyperkinesis of the apical RVFW. Furthermore, BV affected most para-meters of systolic function, but not the segmental strain values and N-TAPSE.Conclusions: Right ventricular basal longitudinal systolic function is decreased in dogs with PS in comparison to a healthy cohort. Regional and global function does not necessarily coincide. 2023 Elsevier B.V. All rights reserved.