2017 ACVIM Forum Research Abstract Program

The evaluation of myocardial function through two-dimensional speckle tracking has been shown to be an effective method for the early identification of ventricular dysfunction, being safe and feasible for evaluation of myocardial function in dogs with suspected of some form of latent myocardial dysfunction not evidenced by conventional echocardiographic examination. Stress echocardiography with dobutamine is commonly indicated to detect cardiac dysfunction in asymptomatic patients, evaluating myocardial contractile reserve and viability. Pharmacological stress test was performed with dobutamine to evaluate the myocardial function via two-dimensional speckle tracking in healthy dogs and in different stages of the MMVM. The study included 15 Beagle dogs, distributed in 3 groups and selected according to the internal diameters of the left ventricle in diastole and the aortic ratio (DIVEd/Ao). The groups were constituted: Group I (Control) -5 healthy dogs without MMVD; Group II -5 dogs with MMVD (DIVEd)/Ao ratio lower than 2.8; Group III -5 dogs with MMVD and DIVEd/Ao ratio higher than 2.8. The animals were submitted to the echocardiographic examination performed by a single operator and evaluation was performed before and after dobutamine infusion. Dobutamine was diluted in 5% glucose solution, following the progressive scheme: 5 lg/kg/minute for 3 consecutive minutes; 7.5 lg/kg/minute for 3 consecutive minutes; 10 lg/kg/minute for 3 consecutive minutes. The images were analyzed using the Syngo Velocity Vector Imaging (VVI) algorithm optical flow algorithm (SIEMENS Ã’ ). Data were submitted to the normality test and to repeated measures analysis of variance and Tukey's test. The aim of this study was to evaluate the adaptations involving the left ventricle, across the gestational process and its diastolic function, using tissue Doppler echocardiography. Animals: 15 pregnant bitches, healthy aged 2-6 years and weighing between 5 and 15 kg. Heart rate and blood pressure clinical evaluation was performed, as well as echocardiography M-mode, spectral and tissue Doppler, in the estrous (EZ), every 15 days during pregnancy (PD 15, 30, 45 and 60) and 45 days post partum (PP). The variables from the evaluation were submitted to statistical analysis. Heart rate (HR) (P = 0.149) and systolic blood pressure (SAP) (P = 0.564) did not show significant changes during pregnancy. The parameters that have undergone significant changes were EF (P = 0.0016) and FS (P = 0.0019). AVVmax, PVmax, wave E'(s) S' (s) and S' (lat) being influenced by the gestational period (P < 0.05). These changes could be explained by cubic regression model. The E:A (P = 0.041) IVRT (0.044) relation and A '(lat) (0.023) also suffered influence of pregnancy, but had a nonparametric residual distribution. Pregnancy produces changes in maternal hemodynamics also influencing diastolic function. Myocardial contractility increases as a result of an improvement in systolic performance, while diastolic function changes significantly revealing a more compliant ventricle, which is the physiological response to increased volume and metabolic requirements due to gestation. Pulmonary hypertension (PH) is a hemodynamic and pathophysiologic condition defined an increase in systolic pulmonary artery pressure greater than 30 mmHg. Classically, this condition can lead to right ventricular dysfunction, which is associated to poor outcomes, especially in patients with chronic congestive heart failure.