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Time-domain heart rate variability (HRV) parameters and the correlation between echocardiography and Holter examinations in dogs with myxomatous mitral valve disease (MMVD) were determined. Holter examination was also performed at different time frames: an entire 24-hour period, a four-hour period during sleep, and a four-hour period while awake. Ten healthy (control group) and 28 MMVD dogs, 15 with and 13 without heart failure, were evaluated. The SDANN (sd of the mean normal RR intervals for all five-minute segments during 24-hour Holter) and pNN(50) (percentage of differences between adjacent normal RR intervals that are >50 ms computed over 24-hour Holter) variables were significantly lower in the dogs with MMVD heart failure. The differences in HRV between the groups were only detected during the 24-hour evaluation period (P<0.05). There were high correlations (canonical analysis) between Holter and echocardiography examinations when considering pNN(50), SDANN, and LA/AO (left atrial to aortic root ratio) (r=0.92; P<0.05), indicating that both are important in evaluating MMVD dogs. SDANN and pNN(50) are measures of parasympathetic control of the heart, and thus, it is possible to infer that the MMVD dogs exhibit parasympathetic withdrawal during the development of heart failure.

Norwegian Forest cats (NFCs) are often listed as a breed predisposed to cardiomyopathy, but the characteristics of cardiomyopathy in this breed have not been described. The aim of this preliminary study was to report the features of NFC cardiomyopathy based on prospective echocardiographic screening of affected family groups; necropsy findings; and open-source breed screening databases. Prospective examination of 53 NFCs revealed no murmur or left ventricular (LV) outflow tract obstruction in any screened cat, though mild LV hypertrophy (defined as diastolic LV wall thickness ≥5.5mm) was present in 13/53 cats (25%). Gross pathology results and histopathological sections were analysed in eight NFCs, six of which had died of a cardiac cause. Myocyte hypertrophy, myofibre disarray and interstitial fibrosis typical of hypertrophic cardiomyopathy were present in 7/8 cats, but endomyocardial fibrosis suggestive of restrictive cardiomyopathy was also present in the same cats. Pedigree data analysis from 871 NFCs was supportive of a familial cardiomyopathy in this breed.

Sixty clinically normal German shepherd dogs, 31 males and 29 females, ranging in age from 1 and 5 years and with a body weight ranging from 22 to 37.2 kg, were examined by the two-dimensional mode, M-mode, and Doppler echocardiography. In Doppler mode, the mitral valve flows were obtained, where the aim was to determine the velocity peaks and ratios of the E and A waves and the mitral E wave deceleration time. The velocity peaks were obtained for the tricuspid, pulmonary and aortic valves. On the left ventricular outflow tract flow, the time velocity integral and aortic cross-sectional area was used to calculate the cardiac output. A statistically significant correlation with the body weight was found for the systolic left atrial and diastolic aortic diameter on two-dimensional mode. On M-mode, there was a significant correlation between the body weight and the systolic left atrium and diastolic aortic dimension, systolic and diastolic left ventricular, septal and posterior wall dimensions. Doppler echocardiography showed that there was no significant correlation between the body weight and the mitral, tricuspid, pulmonary and aortic valves flows. These results demonstrate that it is important to know the normal echocardiographic values for German shepherd dogs because there are some characteristics peculiar to this particular breed. The data obtained is expected to be helpful for studies on small animal cardiology.

RESUMOFoi desenvolvida e descrita uma técnica cirúrgica para fistulação e canulação do rúmen em animais utilizados nos estudos de nutrição animal. O método cirúrgico foi empregado para canulação de 25 vacas e oito cordeiros. A fistulação permanente foi realizada no centro da fossa paralombar esquerda em estágio operatório único. Uma cânula de borracha foi implantada na parede ruminal após o afastamento da musculatura da parede abdominal e a sutura do rúmen ao peritôneo e à pele. Não foram observadas complicações graves advindas da canulação ruminal, mas houve a ocorrência de discreto vazamento de conteúdo em alguns animais. As cânulas permaneceram funcionais por longo período e permitiram a obtenção de quantidades suficientes de amostra.Termos para indexação: Cirurgia, cânula ruminal. ABSTRACTA surgical technique for rumen fistulation and cannulation was developed for animal nutritional studies. The surgical method was used to cannulated 25 adult cows and eight lambs. The permanent fistula was made in the middle of the left paralumbar fossa in a one-stage operation. It was performed the spreading of the abdominal muscle layers and the sutures from the rumen to the peritoneum and to the skin, and the rubber cannula was inserted into the rumen wall. No severe complication was observed in ruminal cannulation, but minor leakages were observed in some animals. The cannulas had a long functional life and permited convenient sampling of digesta.

Cardiac diseases promote alterations in the autonomic control of the heart, leading to an increase in heart rate and, as a result, a decrease in heart rate variability (HRV).The aim of this study was to evaluate if the development of heart failure secondary to degenerative mitral valve disease (DMVD) concurs with changes in autonomic modulation of heart rhythm which are assessed by long electrocardiography examination (Holter). Dogs were evaluated by clinical examination and echocardiography in order to be categorized into the following groups: Control (healthy; n=6), DMVD (disease without heart failure; n=8), and DMVD heart failure (disease with heart failure; n=13). Arrhythmias and frequency domain HRV were determined by Holter. Diseased animals, when compared to healthy, had significantly lower total power, which indicates overall HRV. DMVD heart failure dogs also showed other disturbances such as high incidence of supraventricular arrhythmias, high heart rate, little amount of pauses (2.0s long between consecutive heartbeats), longer time in tachycardia, shorter time in bradycardia, low high frequency (parasympathetic control), and high low frequency (sympathetic and parasympathetic control) when compared to control (p<0.05). In DMVD dogs, Holter-derived variables changed with the development of heart failure.Keywords: electrocardiography, heart failure, frequency-domain, cardiology RESUMO As cardiopatias cursam com alterações do controle autonômico do coração, resultando em taquicardia e consequente diminuição na variabilidade da frequência cardíaca (VFC). O objetivo deste estudo foi avaliar se o desenvolvimento de insuficiência cardíaca secundária à degeneração valvar mitral (DVM) leva a alterações no controle autonômico do coração, as quais podem ser determinadas pela eletrocardiografia contínua (Holter). Cães foram distribuídos em grupos experimentais após avaliação clínica e ecocardiográfica da seguinte maneira: controle (saudáveis; n=6), DVM sem insuficiência cardíaca (n=8) e DVM com insuficiência cardíaca (n=13). Arritmias e VFC foram determinadas pelo

RESUMOAvaliou-se o perfil eletrocardiográfico de 60 eqüinos da raça Mangalarga Marchador, clinicamente sadios, com idades variando de um a 28 anos, sendo 39 fêmeas e 21 machos. A freqüência cardíaca tendeu a diminuir com a idade e a amplitude da onda P aumentou ao longo do crescimento do animal. Os parâmetros de duração de QRS e amplitude de S foram maiores em machos que em fêmeas.Palavras-chave: eqüino, eletrocardiograma, Mangalarga Marchador ABSTRACT For the electrocardiographic evaluation of Mangalarga Marchador breed horses, 60 electrocardiograms were recorded from clinically healthy equines aging from one to 28-year-old, being 39 females and 21 males. The heart rate tended to decrease with age and the amplitude of P wave increased with the growth of the animals. The duration of the QRS complex and the amplitude of S wave were greater in males than in females.