No abstract

Cardiotoxicity is one of the most significant adverse effects of the oncologic treatment with doxorubicin, which is responsible for a substantial morbid and mortality. The occurrence of heart failure with ventricular dysfunction may lead to severe cardiomyopathy and ultimately to death. Studies have focused on the effects of leucine supplementation as a strategy to minimize or revert the clinical condition of induced proteolysis by several clinical onsets. However, the impact of leucine supplementation in heart failure induced by doxorubicin is unknown. Therefore, the objective of this work is to evaluate the effects of leucine supplementation on the cardiotoxicity in the heart of rats treated with doxorubicin. Rats treated with a 7.5 mg/kg cumulative dose of doxorubicin for 14 days presented a dilatation of the left ventricle (LV), and a reduction of the ejection fraction (FE). The 5% supplementation of leucine in the rats' food prevented the malfunctioning of the LV when administered with doxorubicin. Some alterations in the extracellular matrix remodeling were confirmed by the increase of collagen fibers in the doxorubicin group, which did not increase when the treatment was associated with leucine supplementation. Leucine attenuates heart failure in this experimental model with doxorubicin. Such protection is followed by the maintenance of interstitial collagen fibers.

CRP levels are increased in dogs with PF and exceed levels found in most dogs with SP.

BackgroundCardiac output (CO) is an important haemodynamic parameter to monitor in patients during surgery. However, the majority of the techniques for measuring CO have a limited application in veterinary practice due to their invasive approach and associated complexity and risks. Transoesophageal echocardiography (TEE) is a technique used to monitor cardiac function in human patients during surgical procedures and allows CO to be measured non-invasively. This prospective clinical study aimed to compare the transoesophageal echocardiography using a transgastric view of the left ventricular outflow tract (LVOT) and the thermodilution (TD) technique for the assessment of CO during mean arterial pressure of 65–80 mmHg (normotension) and <65 mmHg (hypotension) in dogs undergoing elective surgery. Eight dogs were pre-medicated with acepromazine (0.05 mg/kg, IM), tramadol (4 mg/kg, IM) and atropine (0.03 mg/kg, IM), followed by anaesthetic induction with propofol (3–5 mg/kg IV) and maintenance with isoflurane associated with a continuous infusion rate of fentanyl (bolus of 3 μg/kg followed by 0.3 μg/kg/min). The CO was measured by TEE (COTEE) and TD (COTD) at the end of expiration during normotension and hypotension (induced by isoflurane).ResultsThere was a strong positive correlation between COTEE and COTD ​​(r = 0.925; P < 0.0001). The bias between COTD and COTEE was 0.14 ± 0.29 L/min (limits of agreement, −0.44 to 0.72 L/min). The percentage error of CO measured by the two methods was 12.32%. In addition, a strong positive correlation was found between COTEE and COTD during normotension (r = 0.995; P < 0.0001) and hypotension (r = 0.78; P = 0.0223).ConclusionsThe results of this study indicated that the transgastric view of the LVOT by TEE was a minimally invasive alternative to clinically monitoring CO in dogs during anaesthesia. However, during hypotension, the CO obtained by TEE was less reliable, although still acceptable.

Pesq. Vet. Bras. 34(5):469-472, maio 2014 469 RESUMO.-[Intervalo QT em cães hígidos: qual método de correção para o intervalo QT é mais apropriado na clínica de pequenos animais?] O intervalo QT do eletrocardiograma (ECG) é influenciado por variações da frequência cardíaca (FC), o que pode levar a erros na interpretação de sua duração. Considerando que as alterações na duração do intervalo QT refletem anormalidades da repolarização ventricular, as quais predispõem a ocorrência de arritmias, esta variável deve ser devidamente avaliada. O objetivo deste trabalho foi determinar qual método de correção do intervalo QT é mais adequado para os cães, considerando-se diferentes intervalos de FC normais. Cães adultos saudáveis, de diferentes raças (n=130; Pastor Alemão, Boxer, Pit Bull Terrier e Poodle) foram submetidos ao exame eletrocardiográfico, no qual se determinaram os intervalos QT a partir da derivação bipolar II e foram corrigidos os efeitos da FC por meio da aplicação de três fórmulas, envolvendo regressão quadrática, cúbica ou linear. Os valores do QT corrigido (QTc) obtidos utilizando as diversas fór-mulas foram significativamente diferentes (ρ<0,05), sendo os derivados da equação QTcV = QT + 0,087 (1-RR), os mais consistentes (regressão linear). The electrocardiography (ECG) QT interval is influenced by fluctuations in heart rate (HR) what may lead to misinterpretation of its length. Considering that alterations in QT interval length reflect abnormalities of the ventricular repolarisation which predispose to occurrence of arrhythmias, this variable must be properly evaluated. The aim of this work is to determine which method of correcting the QT interval is the most appropriate for dogs regarding different ranges of normal HR (different breeds). Healthy adult dogs (n=130; German Shepherd, Boxer, Pit Bull Terrier, and Poodle) were submitted to ECG examination and QT intervals were determined in triplicates from the bipolar limb II lead and corrected for the effects of HR through the application of three published formulae involving quadratic, cubic or linear regression. The mean corrected QT values (QTc) obtained using the diverse formulae were significantly different (ρ<0.05), while those derived according to the equation QTcV = QT + 0.087(1-RR) were the most consistent (linear regression). QTcV values were strongly correlated (r=0.83) with the QT interval and showed a coefficient of variation of 8.37% and a 95% confidence interval of 0.22-0.23 s. Owing to its simplicity and reliability, the QTcV was considered the most appropriate to be used for the correction of QT interval in dogs. intervalo de confiança de 95% de 0,22-0,23s. Devido à confiabilidade dos dados, o QTcV foi considerado o mais apropriado para ser utilizado para a correção do intervalo QT em cães, além de ser um método de fácil execução.