Comparison of Tissue Doppler Assessment of Longitudinal Left Ventricular, Interventricular and Mitral Annular Strain and Strain Rate of Small Breed Dogs With and Without Chronic Degenerative Valvular Disease
Tissue Doppler (TD) assessment of strain (St) and strain rate (SR) are new ultrasonographic analysis of segmental cardiac myocardial motion and deformation.
The aim of this study is to quantify the left ventricular myocardial systolic and diastolic function and the mitral annulus (MA) motion by TD, St and SR in small breed dogs with or without chronic degenerative valvular disease (CDVD) (class α / X).
Ten small breed dogs were enrolled. Five dogs were clinical healthy and the other five dogs were affected with CDVD. Physical examination, systemic blood pressure, routine blood examination, radiography, echocardiography, and electrocardiography were performed in all dogs. Peak systolic and diastolic longitudinal tissue velocity (TV) and SR values were measured in 3 segments (basal, middle and apical) of the left ventricular free wall (LVFW) and interventricular septum (IVS), and also at MA. Systolic longitudinal peak St values in all segments and MA were also recorded.
Peak systolic TV and SR of LVFW and IVS in each group were lower in basal segment than in apical segment (p = 0.02 and 0.03). Compared to healthy dogs, left ventricular and interventricular TV, St and SR of dogs with heart failure were not significantly different in all segments.
This study indicated quantitative values of left ventricular, interventricular and mitral annular TV, St and SR in small breed dogs with CDVD are not significantly different with healthy dogs. Further studies of TD, St, and SR on left ventricular remodeling in dogs with advanced CDVD is warranted.