Jessica Nascimento Moraes Monteiro

Doppler tecidual do miocárdio de gatos submetidos à anestesia dissociativa

The tissue Doppler imaging (TDI) is a recent technique that allows the evaluation of the myocardium movement velocity during the cardiac cycle phases, providing important informations of the cardiac function. In veterinary medicine, studies have been realized for the characterization of cardiac contractility dysfunctions and to establish the normality patterns. The present work meant to evaluate the myocardium contractility velocity by the technique of TDI in healthy cats submitted to dissociative anesthesia. For that purpose, there were used nine cats, all adult, healthy and without sexual or breeding distinction. There were measured the values of Ea (early diastolic peak velocity), Aa (late diastolic peak velocity) and Sa (systolic peak velocity) in the lateral and septum wall sides. The mean values observed to septum Ea and septum Sa were of 7.2±2.5cm s-1 and 6.3±1.7cm s-1, respectively. The mean value obtained for lateral Ea was of 12.0±4.1cm s-1, while the mean value of lateral Sa was of 8.3±1.6cm s-1. It was obtained a mean value of 7.0±3.1cm s-1 for the lateral Aa, and 4.7±1.5cm s-1 for septum Aa. The standard of the myocardium contraction velocities mean values in the feline specie is of great importance, and it may help in the early diagnosis of heart contraction alterations. Due to the lack of studies with the TDI technique in cats, the values obtained in our work allow the realization of comparative studies, helping to apply this technique in experimental protocols and to the early diagnosis of cardiomyopathies in the feline specie.

Ultrassonografia quantitativa do fígado em gatos com tirotoxicose induzida

Este estudo avaliou ultrassonograficamente o figado de gatos submetidos a tirotoxicose induzida pela tecnica de histograma dos niveis de cinza com o objetivo de melhor avaliar possiveis alteracoes hepaticas decorrentes do excesso de hormonios tiroidianos. Para isto, foram utilizados nove gatos higidos, adulto-jovens, que receberam diariamente 150µg/kg de levotiroxina sodica, por 60 dias. O histograma hepatico nao demonstrou diferenca estatistica ao nivel de 5% de significância entre os momentos avaliados; entretanto, as variacoes dos valores das variaveis estudadas sugeriram a promocao de aumento da heterogeneidade e diminuicao da ecogenicidade do parenquima hepatico quando comparado ao momento inicial. A avaliacao citopatologica e histopatologica revelou quadro de hepatite tirotoxica em todos os animais.

Pulsed-wave tissue Doppler imaging of the myocardium of cats with induced thyrotoxicosis

Left ventricular myocardial motion was quantified using pulsed-wave tissue Doppler imaging (PW-TDI) in nine adult cats before and after thyrotoxicosis induction. In order to induce thyrotoxicosis, all cats were given 150µg kg-1 of levothyroxine sodium as a single oral dose each day for 10 weeks. PW-TDI examinations were performed immediately before the induction and by the end of the experimental protocol. An increase in myocardial motion velocity was documented at the interventricular septum level, demonstrated by an elevation in systolic (Sa), and early (Ea) and late (Aa) diastolic waves (P<0.05). However, no alteration in Sa, Ea and Aa values was seen at the lateral mitral annulus. Heart rate increased significantly between the experimental stages, and three of the animals presented fused Ea and Aa waves at the end of the experiment. The experimental protocol used in this study caused alterations in left ventricular myocardial motion velocity, but did not impair left ventricular diastolic function.