Assessment of longitudinal systolic function using tissue motion annular displacement in dogs with degenerative mitral valve disease

INTRODUCTION

Although degenerative mitral valve disease (DMVD) is essentially a disorder of the valve, the progression of the disease leads to structural myocardial changes that may compromise left ventricular systolic function. Tissue motion annular displacement (TMAD) is a surrogate for longitudinal fiber function based on speckle tracking assessment of the movement of the mitral annulus toward the apex during systole. The aim of this study was to evaluate longitudinal systolic function with TMAD in dogs with DMVD.

ANIMALS

Ninety-four dogs with DMVD and 32 healthy dogs.

METHODS

Prospective cross-sectional observational study. Dogs with DMVD of various American College of Veterinary Internal Medicine classification stages and healthy control dogs underwent physical examination, electrocardiography, systolic blood pressure measurement, as well as a standard and speckle tracking echocardiography. Global longitudinal strain (GLS) and TMAD were used to assess longitudinal systolic function.

RESULTS

The global TMAD_mm and global TMAD_% were higher in American College of Veterinary Internal Medicine B2 animals than in the stage CD. Global TMAD _(mm/kg,_mm/bodyweight3, _mm/m²) were correlated with GLS and ejection fraction. Global TMAD _(mm/kg,_mm/m²,%) and GLS were influenced by sex. In addition, systolic blood pressure influenced GLS (P < 0.01; r = -0.23), global TMAD_mm/kg (P = 0.017; r = -0.21) and global TMAD_mm/m² (P = 0.031; r = -0.19). Tissue motion annular displacement was fast to be performed and produced good repeatability in dogs with DMVD.

CONCLUSIONS

Global TMAD _(mm,%), was reduced in DMVD dogs with clinical signs of heart failure compared with stage B2. Tissue motion annular displacement was shown to be a repeatable technique for evaluation of longitudinal systolic function in dogs with DMVD.