Blood lactate increases with the progression of mitral valve disease in dogs / Aumento de lactato sanguíneo com progressão de valvopatia mitral em cães

In dogs with congestive heart failure, the upregulated sympathetic tone causes vasoconstriction that impairs peripheral blood supply, therefore causing the accumulation of lactate. In this prospective cross-sectional study with a longitudinal component, blood lactate was quantified in 10 healthy and 34 myxomatous mitral valve disease (MMVD) dogs to investigate its potential use as a diagnostic and prognostic biomarker. While there were no differences in lactate concentration between control animals and stages B1 (3.31±0.62mmol/L) and B2 (3.32±0.46mmol/L) dogs, significant differences were found between healthy (2.50±0.69mmol/L) and both C (3.99±0.47mmol/L) and D (6.97±1.23mmol/L) animals. When a cut-off of 3.35mmol/L was used, lactate was able to distinguish dogs with normal and remodeled hearts with a sensitivity of 78.2% and specificity of 63.6%. Also, significant correlations existed between lactate and indicators of cardiac remodeling. Finally, animals with blood lactate <3.5mmol/L carried a better prognosis when compared with dogs in which lactate was >5.0mmol/L. Our results suggest that the progression of MMVD results in accumulation of lactate within the bloodstream, which is likely attributable to the impaired peripheral tissue perfusion. In MMVD dogs, blood lactate may be used as a surrogate for cardiac remodeling, and an increased concentration is associated with a worse prognosis regarding the time to evolve into congestive heart failure.(AU)

Em cães com insuficiência cardíaca congestiva, o tônus simpático hiperregulado causa vasoconstrição e interfere com o suprimento sanguíneo periférico, resultando no acúmulo de lactato. Neste estudo prospectivo transversal com um componente longitudinal, o lactato sanguíneo foi quantificado em 10 cães saudáveis e 34 cães com doença mixomatosa da valva mitral (DMVM) para investigar seu potencial como biomarcador diagnóstico e prognóstico. Embora não tenham sido identificadas diferenças na concentração de lactato entre animais controle e cães com DMVM nos estágios B1 (3,31±0,62mmol/L) e B2 (3,32±0,46mmol/L), diferenças significativas foram constatadas entre os cães saudáveis (2,50±0,69mmol/L) e cães com DMVM estágio C (3,99±0,47mmol/L) ou D (6,97±1,23mmol/L). Quando utilizado o valor de corte de 3,35mmol/L, o lactato foi capaz de diferenciar cães com corações normais daqueles com corações remodelados com sensibilidade de 78,2% e especificidade de 63,6%. Além disso, correlações significativas foram encontradas entre o lactato e os indicadores de remodelamento cardíaco. Por fim, os animais com lactato sanguíneo <3,5mmol/L tiveram prognóstico melhor comparativamente aos cães com concentrações >5,0mmol/L. Nossos resultados sugerem que a progressão da DMVM resulta no acúmulo de lactato na corrente sanguínea, fato que é provavelmente atribuído à perfusão periférica prejudicada. Em cães com DMVM, o lactato sanguíneo pode ser utilizado como indicador de remodelamento cardíaco, cuja concentração elevada está associada com pior prognóstico relativo ao tempo para evoluir para insuficiência cardíaca congestiva.(AU)

Avaliação da pressão arterial sistêmica em cães obesos: comparação entre os métodos oscilométrico e doppler ultrassônico / Systemic blood pressure evaluation by oscillometric versus doppler ultrasonographic methods in obese dogs

A obesidade é o problema nutricional que mais acomete os cães e pode causar vários efeitos deletérios a saúde animal. No entanto, o efeito desta condição sobre a pressão arterial sistólica (PAS) em cães obesos é controverso. Os métodos indiretos de mensuração da PAS são os mais comumente utilizados na medicina veterinária para o diagnóstico da hipertensão sistêmica, por serem mais práticos e de fácil acesso. Não foram localizados na literatura estudos que tenham comparado os dois métodos para esta avaliação em cães obesos. Diante do exposto, o objetivo desse estudo foi avaliar a PAS em cães obesos, comparando os métodos indiretos de mensuração da pressão arterial, oscilométrico e doppler ultrassônico, a fim de verificar as diferenças nos valores obtidos, como também o método mais indicado para aferir a PAS em cães nesta condição. Foram avaliados 50 cães, incluindo 25 obesos com escore de condição corporal (ECC) médio de 8,42±0,50 e 25 cães com peso corporal ideal com ECC médio de 4,56±0,51. Os resultados revelaram valores superiores da PAS obtidos pelo método doppler (152±16mmHg) comparados ao oscilométrico (136±11mmHg). A análise de correspondência determinada por análise estatística multivariada demonstrou maior correspondência entre a condição corporal e o método de avaliação da PAS. Esses achados sugerem que o método indireto doppler pode aferir com mais precisão os valores de PAS em cães obesos.(AU)

Obesity is the most common nutritional problem in dogs and it can cause various harmful effects on animal health. However, the effect of this condition on systolic blood pressure (SBP) in obese dogs is controversial. The indirect method of measuring PAS is the most commonly used in veterinary medicine for the diagnosis of systemic hypertension, because it is more practical and easy to access. There is little scientific information about the comparison of the two non-invasive methods of measurement of blood pressure in obese dogs. Therefore, the objective of this study was to evaluate the SBP in obese dogs by comparing both indirect methods of measuring blood pressure, with oscillometric and doppler vascular in order to verify the differences in blood pressure values, but also the best method to assess the SBP dogs in this body score condition. The study complain blood pressure measurement of 50 dogs, with were divided in obese dogs with mean body condition score (BCS) of 8.42±0.50 (n=25) and dogs with ideal BCS of 4.56±0.51 (n=25). At comparison of blood pressure values, SBP values obtained by doppler method (152±16mmHg) were higher than the oscillometric (136±11mmHg). Correspondence analysis determined by multivariate statistical analysis showed correlation between body condition and the procedure of the SBP. These findings suggest that the indirect method doppler can better reflect the SBP in obese dogs.(AU)

Doxorubicin induced dilated cardiomyopathy in a rabbit model: an update.

Dilated cardiomyopathy (DCM) is characterized by chamber dilation and cardiac dysfunction. Because of the poor prognosis, models are needed for the investigation of and development of new therapeutic approaches, as well as stem cell therapy. Doxorubicin (DOX), used as chemotherapeutic agent, is reported to be cumulative cardiotoxic causing DCM. The aim of the study was to investigate the onset of systolic dysfunction using echocardiography in rabbits receiving two different doses of DOX (1mg/kg twice a week and 2 mg/kg once a week). Twenty rabbits were treated with doxorubicin in two different doses for 6 weeks and compared with a control group treated with NaCl 0.9%. The effect of doxorubicin on the myocardium was investigated with histological analysis and scanning electron microscopy of left ventricle (LV), as well as in the interventricular septum (IVS) and right ventricle (RV). The results showed a high mortality rate for rabbits receiving 2 mg/kg once a week. A significant reduction in systolic function was present in animals treated with DOX after 6 weeks, with decreased ejection fraction and shortening fraction. Histology and electron microscopy revealed vacuolization, intracytoplasmic granulation, necrosis and interstitial fibrosis in LV, as well as in the IVS and RV. Doxorubicin induced changes are present in the LV, RV and IVS, and the administration at the dose of 1 mg/kg twice a week for only 6 weeks is safe and sufficient to induce DCM in rabbits.