Characterization of Doppler spectrum of hepatic veins in dogs with pulmonary hypertension.

Pulmonary hypertension (PH) triggers hemodynamic changes within the right heart, which may affect hepatic venous flow. The aims of this study were three-fold: to investigate, prospectively, the reliability of the hepatic vein Doppler waveform to diagnose and characterize the magnitude of PH in dogs; to evaluate whether a correlation exists between hepatic venous flow waves and the structural and functional characteristics of the right ventricle (RV); and to determine whether age, gender, body weight, heart rate (HR), heart rhythm and systolic blood pressure affect the hepatic venous waveform pattern. A cross-sectional observational study was carried out in 43 dogs with varying degrees of PH and a control group of 15 healthy dogs. The velocities of the hepatic A, S, V and D spectral waves and the phasic pattern varied according to the severity of PH. Weak to moderate correlations were documented between hepatic vein waves and age, HR, and the structural and functional variables of the RV. A D Wave cut-off of 11.6 cm ∙ s-1 had a sensitivity of 100% and specificity of 35% for differentiation of dogs with severe PH from healthy dogs. Doppler assessment of hepatic venous flow was shown to be a reliable technique for screening dogs for PH.

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 TMADmm 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 TMADmm/kg (P = 0.017; r = -0.21) and global TMADmm/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.

Assessment of right ventricular systolic function by tissue motion annular displacement in healthy dogs.

INTRODUCTION/OBJECTIVES: There are few parameters for assessment of right ventricular (RV) systolic function on echocardiographic examination. Morphofunctional studies are limited by the irregular shape of the RV. Recently, tissue motion annular displacement (TMAD), a technique that evaluates valve annulus displacement toward the cardiac apex, has shown a good correlation with left ventricular global longitudinal strain (GLS) in healthy dogs. Therefore, the aim of this study was to evaluate the longitudinal systolic function of the RV of healthy dogs using TMAD. ANIMALS: A hundred healthy client-owned dogs. MATERIALS AND METHODS: Cross-sectional study. Physical examination, electrocardiogram, blood pressure measurement, and echocardiography were recorded. The systolic function of the RV was evaluated by GLS free wall and TMAD. Data were compared with those derived from conventional echocardiography. RESULTS: TMAD values varied according to body weight. There was a correlation of TMAD in millimeters with all indices of RV systolic function, including GLS free wall (R:-0.239; p:0.017). TMAD had a correlation with age and heart rate; whereas there was no relationship with sex and blood pressure. The coefficient of variation for the intraobserver evaluation was lower for the TMAD in millimeters (9.9%) compared with the GLS free wall (17.9%). In addition, the mean time to perform TMAD (8.1 s) was lower than that of the GLS free wall (37.7 s). CONCLUSIONS: TMAD is a fast, reproducible, and promising method for assessing RV systolic function in healthy dogs. However, further studies are needed to understand the applicability of this technique in patients with heart disease.