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The electrocardiogram, which graphically records the phases of the cardiac cycle, plays a crucial role in diagnosing arrhythmias and conduction abnormalities. However, the reliability of results can be significantly affected by the level of expertise of the evaluator. Acknowledging potential discrepancies in interpretations of the same electrocardiographic readings across different cardiac cycles and between analysts of varying experience, this study aimed to assess the interobserver and inter-cycle variability in electrocardiographic exams of dogs. This retrospective research was carried out at the Veterinary Hospital Superintendency Unit of the Federal University of Fronteira Sul, Realeza Campus, PR, Brazil. The study involved a random selection of electrocardiographic records from 50 dogs, collected between September 2018 and December 2019, without discrimination based on breed, sex, age, or weight. Various parameters were analyzed, including heart rate and rhythm; durations of P waves; QRS complexes; PR and QT intervals; amplitudes of P, R, and T waves; and both atrial and ventricular electrical axes. The data underwent Shapiro-Wilk normality testing, with parametric data analyzed via analysis of variance and Tukey's test, and non-parametric data assessed using the Kruskal-Wallis followed by Dunn's tests. The final step involved applying the Kappa Agreement Coefficient Test to the data. The findings revealed variability in heart rhythm interpretation, with disagreement between evaluators of low to intermediate experience levels. Specifically, low-level evaluators tended to underestimate maximum heart rates, recording a median rate of 105, compared to 122 by high-level evaluators (p=0.0100). Additionally, P wave durations were consistently overestimated by low- and intermediate-level evaluators, who reported median durations of 52 and 51, respectively, against 48 by their highly experienced counterparts (p=0.0064). No significant differences emerged in analyses comparing a single cardiac cycle to either three cycles or the average of three cycles. The study highlighted the impact of evaluator expertise on the variability of electrocardiographic interpretations, particularly concerning P wave duration, for which the evaluators tended to overestimate measurements, and the degrees of agreement, which did not represent their experience level. The findings stress the importance of training and routine practice in electrocardiographic examinations to mitigate the risk of mistaken interpretations and analyses.(AU)

O eletrocardiograma representa o registro gráfico das fases do ciclo cardíaco e é utilizado para o diagnóstico de arritmias ou distúrbios de condução. No entanto, a confiabilidade dos resultados pode ser influenciada pelo grau de experiência dos avaliadores. Devido à possibilidade de variação de resultados de um mesmo exame entre os ciclos cardíacos e entre analisadores de diferentes níveis de experiência, o estudo teve como objetivo avaliar a variabilidade interobservador e entre ciclos cardíacos durante a avaliação de exames eletrocardiográficos de cães. A pesquisa foi conduzida de forma retrospectiva na Superintendência Unidade Hospitalar Veterinária Universitária da Universidade Federal da Fronteira Sul, Campus Realeza ­ PR. Para a análise eletrocardiográfica foram selecionados aleatoriamente exames de 50 cães, gravados em arquivos computadorizados durante o período de setembro de 2018 a dezembro de 2019, independente da raça, sexo, idade e peso. Foram avaliados frequência e ritmo cardíaco, durações de onda P, complexo QRS, intervalo PR e intervalo QT, amplitudes de onda P, R e T, e eixo elétrico atrial e ventricular. Os dados foram analisados por teste de normalidade de Shapiro-Wilk, sendo os dados paramétricos analisados por análise de variância seguido por Teste de Tukey e os dados não paramétricos pelo Teste de Kruskal-Wallis, seguido pelo Teste de Dunn. Como última etapa, os dados foram submetidos ao Teste de Coeficiente de Concordância de Kappa. Evidenciou-se variabilidade na interpretação de ritmos cardíacos com discordância de avaliadores de nível baixo e intermediário, diferença da frequência cardíaca máxima do avaliador de baixo nível de experiência que subestimou os valores, obtendo mediana de 105, enquanto o de alto nível obteve mediana de 122 (p=0,0100). Ainda, evidenciou-se superestimação da duração da onda P pelos avaliadores de nível baixo e intermediário, que encontraram medianas de 52 e 51 respectivamente, enquanto o de alto nível obteve mediana de 48 (p=0,0064). Em relação a diferentes ciclos cardíacos, não houve diferenças entre a análise de apenas um ciclo em relação a três ciclos ou a média de três ciclos. Por meio do estudo foi possível evidenciar a variabilidade na interpretação entre avaliadores com diferentes níveis de experiência, em relação a duração da onda P, em que os avaliadores superestimaram os valores e em relação aos graus de concordância que não representaram os níveis de experiência dos avaliadores na análise do todas as variáveis, ressaltando a importância do treinamento e rotina de exames eletrocardiográficos para evitar interpretações e análises equivocadas.(AU)

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The objective of this study was to evaluate the effect of three doses of equine chorionic gonadotropin (eCG) for ovarian superstimulation on ovarian response, follicular development and cumulus-oocyte complexes (COCs) collection in llamas. For this purpose, eighteen multiparous non-lactating adult (4­7 yo) female llamas with an average body condition of 2.8 (BCS 1­5) were submitted to a follicular ablation (FA) to induce a new follicular wave emergence. Two days after FA (Day 0), synchronized llamas were randomly allocated to three treatment groups (n = 6/group) and given 500, 750 and 1000 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) per animal respectively to induce ovarian superstimulation. Transrectal ultrasonography were performed on Days 2, 4, and 6; and ovum pick up (OPU) was performed on Day 6. Data was evaluated by one-way analysis of variance (ANOVA), repeated measures ANOVA, and 2-tailed Chi-square. The average size (mm) of follicles was greater (p≤ 0.05) in the 1000 IU group compared to the other groups. There was a greater (p≤ 0.05) number of follicles ≥ 7 mm in the 1000 IU group compared to the 500 IU group. Number of COCs collected on Day 6 and the COC recovery rate were not different among groups. In conclusion, a single dose of 1000 IU of eCG induced the best ovarian response resulting in larger and greater number of follicles at the time of OPU.(AU)

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Obesity is considered a chronic inflammatory process that is related to metabolic impairment, respiratory distress, and cardiovascular disease. In cats, few studies have evaluated the implications of obesity on the cardiovascular system, and the existing literature is controversial. Therefore, the aim of this study is to detect pressure, electrocardiographic, and morphofunctional changes in overweight and obese cats. After clinical and laboratory evaluation, 45 animals were selected for the study. Cats were separated according to body condition score (BCS) into three groups (control, overweight, and obese). All animals underwent blood pressure measurement, electrocardiogram, and transthoracic echocardiogram. Results are presented as mean ± standard deviation (SD). Data were considered statistically significant at p<0.05. GraphPad Prism® 7.04 software was used for statistical analyses. Mean arterial pressure in obese cats was higher than in animals with ideal weight (CT 123.60 ± 8.97mmHg vs OB 143.00 ± 22.12mmHg, p<0.0138), but hypertension was not detected. On the electrocardiogram, P wave duration (CT 33.67 ± 1.56ms vs OB 37.76 ± 2.76ms; p<0.0003) and QRS complex (CT 48.14 ± 2.56ms vs OB 54.48 ± 5.51ms; p<0.002) were significantly higher in the obese group. There were no significant echocardiographic changes. There was a direct correlation between blood pressure and BCS (r:0.36, p<0.01). The P wave was positively correlated with the BCS (r:0.56, p<0.0001). Likewise, the QRS complex correlated directly with the BCS (r:0.52, p<0.0003). The results indicate cat obesity can directly affect the cardiovascular system, promoting pressure and electrocardiographic changes. Therefore, monitoring the cardiovascular system of cats with obesity is essential.

A obesidade é considerada um processo inflamatório crônico que está relacionada ao comprometimento metabólico, dificuldade respiratória e doenças cardiovasculares. Em gatos, poucos estudos avaliaram as implicações da obesidade no sistema cardiovascular e a literatura é controversa. Portanto, o objetivo deste trabalho é detectar as alterações pressóricas, eletrocardiográficas e morfofuncionais em gatos com sobrepeso e obesidade. Quarenta e cinco animais, após avaliação clínica e laboratorial, foram selecionados para o estudo. Os gatos foram separados conforme o escore de condição corporal (ECC) em três grupos (controle, sobrepeso e obesidade). Todos os animais realizaram mensuração de pressão arterial, eletrocardiograma e ecocardiograma transtorácico. Os resultados foram apresentados como média ± desvio padrão (DP). Os dados foram considerados estatisticamente significativos se p<0,05. O software GraphPad Prism® 7.04 foi usado para análises estatísticas. A pressão arterial média dos gatos obesos era maior que nos animais com peso ideal (CT 123,60 ± 8,97mmHg vs OB 143,00 ± 22,12mmHg, p<0,0138), porém não se detectou hipertensão. No eletrocardiograma, a duração da onda P (CT 33,67 ± 1,56ms vs OB 37,76 ± 2,76ms; p<0,0003) e complexo QRS (CT 48,14 ± 2,56ms vs OB 54,48 ± 5,51ms; p<0,002) foi significativamente maior no grupo obeso. Não houve alterações ecocardiográficas significativas. Houve correlação direta da pressão arterial com o ECC (r:0,36, p<0,01). A onda P correlacionou-se positivamente com o ECC (r:0,56, p<0,0001). Do mesmo modo, o complexo QRS se correlacionou diretamente com o ECC (r:0,52, p<0,0003). Os resultados indicam que a obesidade em gatos pode afetar diretamente o sistema cardiovascular, promovendo alterações pressóricas e eletrocardiográficas. Sendo assim, é indispensável o acompanhamento do sistema cardiovascular dos gatos com obesidade.

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Non-steroidal anti-inflammatory drugs are extensively used in veterinary practice. COX-2 inhibitors are considered to be safer than non-selective inhibitors; however, there are few studies address of their long-term use in equine species. The goal of this study was to identify the possible adverse effects of meloxicam (a preferential COX-2 inhibitor) in healthy horses, administered at a dose of 0.6 mg/kg, orally, once a day, for 28 days. A paired test was performed with seven animals, and the clinical, hematological, biochemical, and gastroscopic parameters, as well as bleeding time, were evaluated in five timepoints and an electrocardiogram at three timepoints. No relevant adverse effects were observed in terms of the parameters evaluated. Significant differences were found in heart rate, AST and P wave duration, segmented neutrophils (%), and the levels of erythrocytes, hemoglobin, hematocrit, and MCH, compared with these parameters at T0; however, no animal manifested clinical alterations. Gastroscopy revealed discrete lesions (Grade 1) in the squamous gastric mucosa on day 14 of treatment in all animals; however, at the end of the study (day 28) these lesions had regressed to grade 0 in three of the horses and remained at grade 1 in the other four animals. Based on these results, we conclude that the use of meloxicam at a daily dose of 0.6 mg/kg, orally, for 28 consecutive days, did not cause relevant adverse effects in healthy horses.(AU)

Os anti-inflamatórios não esteroides são amplamente utilizados na prática veterinária e os inibidores da COX-2 são propostos como mais seguros que os inibidores não seletivos, porém, poucos estudos abordam seu uso por tempo prolongado na espécie equina. Este estudo teve como objetivo identificar os possíveis efeitos adversos do uso de meloxicam (inibidor preferencial da COX-2) em equinos hígidos, na dose de 0,6 mg/kg, por via oral, uma vez ao dia, durante 28 dias. Um teste pareado foi realizado com sete animais e os parâmetros clínicos, hematológicos, bioquímicos, tempo de sangramento e gastroscópicos foram avaliados em cinco momentos e eletrocardiograma em três. Não foram observados efeitos adversos relevantes nos parâmetros avaliados. As variáveis frequência cardíaca, eritrócitos, hemoglobina, hematócrito, HCM, neutrófilos segmentados, AST e duração da onda P apresentaram diferença significativa em relação ao T0, porém nenhum animal manifestou alterações clínicas. Na gastroscopia foram observadas lesões discretas (grau 1) na mucosa gástrica escamosa no dia 14 de tratamento em todos os animais, porém, ao final do estudo (dia 28) essas lesões regrediram para grau 0 em três pacientes e permaneceram em grau 1 em quatro animais. O uso de meloxicam na dose diária de 0,6mg/kg, por via oral, durante 28 dias consecutivos, não causou efeitos adversos relevantes em cavalos hígidos.(AU)

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Existem poucas informações disponíveis sobre a fisiologia e a estrutura do coração em animais selvagens da família dos canídeos selvagens, e esses dados desempenham um papel fundamental no tratamento das cardiopatias, em pesquisas relacionadas à fisiopatologia e na preservação dessas espécies. O presente estudo objetivou realizar avaliação eletrocardiográfica em cachorros-do-mato, relatando e caracterizando parâmetros do eletrocardiograma (ECG) da espécie. Foram avaliados dez cachorros-do-mato (Cerdocyon thous) hígidos. Os animais foram capturados com puçá e contidos quimicamente com associação midazolam e cetamina. Após passarem por exame físico, os cães foram então submetidos aos exames de ECG, posicionados em decúbito lateral direito, avaliando-se frequência e ritmo cardíaco, amplitude de ondas e duração dos intervalos. Os animais apresentaram frequência cardíaca de 201,7± 29,2, com amplitude de ondas, de 0,062 à 0,2mV para onda P; 0,023 à 0,42mV para onda Q; 0,21 à 0,97mV para onda R e zero a 0,14mV para onda S. O seguimento ST em quatro animais variou de 0,02 a 0,125 mV, três animais com 0,03 à 0,047mV. A onda T foi positiva em nove indivíduos (0,06 a 0,44 mV) e negativa em um indivíduo (0,156 mV). As variações eletrocardiográficas foram similares às de cães domésticos. É necessário consolidar com maior número amostral os dados cardíacos apresentados neste estudo.

There is limited information available regarding the physiology and structure of the heart in wild animals of the canid family, and this data plays a crucial role in the treatment of heart disease, research related to pathophysiology, and the preservation of these species. The present study aimed to perform electrocardiographic evaluation in crab-eating fox, reporting and characterizing electrocardiogram (ECG) parameters of the species. Ten healthy crab-eating foxes (Cerdocyon thous) were evaluated. The animals were captured using a net and chemically restrained with a combination of midazolam and ketamine. After a physical examination, the dogs were subjected to ECG exams, positioned in the right lateral recumbency, assessing heart rate and rhythm, wave amplitude, and interval durations. The animals presented a heart rate of 201.70±29.2, with wave amplitudes ranging from 0.062 to 0.2 mV for the P wave, 0.023 to 0.42 mV for the Q wave, 0.21 to 0.97 mV for the R wave, and zero to 0.14 mV for the S wave. The ST segment in four animals ranged from 0.02 to 0.125 mV, and in three animals, from 0.03 to 0.047 mV. The T wave was positive in nine individuals (0.06 to 0.44 mV) and negative in one individual (0.156 mV). The electrocardiographic variations were similar to those found in domestic dogs. It is necessary to consolidate the cardiac data presented in this study with a larger sample size.

Hay poca información disponible sobre la fisiología y estructura del corazón en animales salvajes de la familia de los cánidos salvajes, y estos datos desempeñan un papel fundamental en el tratamento de las cardiopatias, em investigaciones relacionadas con la fisiopatología y la preservación de estas especies. El presente estudio tuvo como objetivo realizar una evaluación electrocardiográfica en zorro cangrejero, informando y caracterizando los parámetros del electrocardiograma (ECG) de la espécie. Se evaluaron diezzorros cangrejero (Cerdocyon thous) sanos. Los animales fueron capturados con una red y contenidos químicamente con una combinación de midazolam y cetamina. Después de someterse a un examen físico, los perros fueron sometidos a exámenes de ECG, posicionados en decúbito lateral derecho, evaluando la frecuencia y el ritmo cardíaco, la amplitud de las ondas y la duración de los intervalos. Los animales presentaron una frecuencia cardíaca de 201.7 ± 29.2, con amplitudes de onda de 0.062 a 0.2 mV para la onda P, 0.023 a 0.42 mV para la onda Q, 0.21 a 0.97 mV para la onda R y de cero a 0.14 mV para la onda S. El segmento ST en cuatro animales varió de 0.02 a 0.125 mV, y en tres animales de 0.03 a 0.047 mV. La onda T fue positiva en nueve individuos (0.06 a 0.44) y negativa en un individuo (0.156). Las variaciones electrocardiográficas fueron similares a las encontradas en perros domésticos. Es necesario consolidar los datos cardíacos presentados en este estudio con un tamaño de muestra más grande.

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Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60'EXER), and in the recovery phase [RCT] at 30'RCT and 60'RCT, and cTnI at 60'RCT, 120'RCT, and 4hRCT. P wave duration was significantly higher at 60'EXER, 15'RCT, and 30'RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30'RCT, and the ST segment presented a significant difference at 60'EXER, 15'RCT, and 60'RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.(AU)

Cães de busca e resgate intercalam a intensidade da atividade desenvolvida que desencadeia alterações metabólicas significativas, bem como na fisiologia cardíaca. Assim, foram avaliadas as alterações que a simulação de busca produz nos níveis de glicose, lactato, troponina I cardíaca (cTnI), bem como na frequência cardíaca e atividade eletrocardiográfica durante a fase de atividade e recuperação, a fim de predizer a adaptação fisiológica ao exercício. Cinco cães adultos saudáveis do Serviço de Resgate e Salvamento do Corpo de Bombeiros Militares foram submetidos à simulação de operação de busca de 60 minutos na mata e cobriram uma área florestal de aproximadamente 50.000 m2. Os cães estavam soltos, acompanhados pelo condutor e estavam livres para realizar qualquer tipo de atividade física. Foram avaliados os níveis séricos de glicose, lactato e troponina I cardíaca, atividade eletrocardiográfica e frequência cardíaca em repouso, na fase de exercício e no tempo de recuperação. Não foram detectadas alterações nos níveis de glicose, frequência cardíaca e ritmo cardíaco. Em comparação com os valores basais houve aumento de lactato ao final da fase de exercício [EXER] (60'EXER) e na fase de recuperação [RCT] aos 30'RCT e 60'RCT; e cTnI aos 60'RCT, 120'RCT e 4hRCT. Duração da onda P foi significativamente maior em 60'EXER, 15'RCT e 30'RCT, sem alterações na amplitude da onda. Duração do intervalo QRS teve aumento significativo em 30'RCT e o segmento ST apresentou diferença significativa em 60'EXER, 15'RCT e 60'RCT quando comparado ao basal. As alterações moderadas nos níveis de lactato e cTnI, bem como a pouca alteração na atividade eletrocardiográfica e manutenção da frequência cardíaca sugerem boa adaptação dos cães de busca e resgate ao tipo, intensidade e duração da operação de busca simulada realizada.(AU)

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Background: The brachycephalic dog breeds have been increasing in Brazil, and these animals are predisposed to present the brachycephalic dog syndrome, consisting of anatomical defects that lead to physiological changes and clinical signs such as wheezing, dyspnea, and hypoxia. Electrocardiography (ECG) is a simple test that can detect disturbances in the electrical activity of the heart, including changes present in hypoxia. The brachycephalic dog syndrome can lead to pulmonary hypertension due to hypoxia. Based on this, the present work aimed to evaluate the ECG of brachycephalic dogs in search of significant changes in heart rhythm, ECG waves, and cardiac axis. Materials, Methods & Results: Twenty-nine dogs were evaluated in this study, 19 brachycephalic and 10 mesaticephalic, after approval by an ethics committee the animals were selected. Electrocardiographic examinations were performed in 2 stages, at rest and immediately after a 3-min trot. The exam was performed with a computerized electrocardiograph, with a standard time of 5 min. The standard positioning for performing the examination was the right lateral decubitus position. To improve the electrical conductivity, 70% alcohol was used between the animal's skin and the electrodes. In statistical analysis, paired t test was performed for comparison of the same group before and after exercise and unpaired t test between groups at the same moments, considering P < 0.05 as significant. Nineteen brachycephalic animals were evaluated, 10 Pugs and 9 French Bulldogs, 9 males and 10 females. The mean age was 3.4 ± 1.8 years; and the mean weight was 12.5 kg ± 2.7 kg. In the control group, consisting of ten mesaticephalic animals, all were non-breed, three males and seven females; the mean age and weight in this group were 4.4 ± 1.5 years and 7.5 kg ± 0.5 kg, respectively. There was a significant increase in heart rate (bpm) after exercise in brachycephalic dogs (baseline: 119.3 ± 4.3; after exercise: 135.1 ± 4.9; P = 0.0005). The same occurred for P wave amplitude (mV) (baseline: 0.20 ± 0.01; after exercise: 0.22 ± 0.01; P = 0.0001). These differences were not found in the control group. There were no alterations in the duration of the P wave, PR interval, QRS complex, and QT interval, and all were within normal values for the species in both groups. The R-wave amplitude remained unaltered and within normal values in both the control and brachycephalic groups. Discussion: The elevation in heart rate may be associated with the chemoreflex secondary to the increased demand for oxygenation during exercise and the hypoxia generated by it. The increase in P amplitude suggests right atrial overload. The P wave corresponds to the atrial depolarization and its amplitude corresponds to the electrical activity in the right atrium. Thus, it is possible to relate the increase in P amplitude and heart rate to the hypoxia caused by exercise in brachycephalic, since this hypoxia results in chemoreceptor activation that increases chronotropism and heart rate. Also, there may be increased pressure in the pulmonary trunk, this increased pressure occurs due to vasoconstriction generated as a reflex to hypoxia in the pulmonary alveoli, leading to a possible picture of acute pulmonary hypertension that, in a cascade effect, leads to hypertrophy and dilation of the right ventricle, increased strength of contractility and ejection affecting the tricuspid valve causing a reflux and consequent overload of the right atrium.

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Chronic degenerative mitral valve disease is the most common acquired heart disease and the main cause of congestive heart failure (CHF) in middle-aged to elderly dogs, being more frequent in small and miniature breeds, being rare in breeds of medium to large size. This disease is characterized by nodular deformity of the valve leaflets, as well as thickening and, in some cases, distension of the chordae tendineae. Echocardiographic findings include cardiomegaly, thickening of the atrioventricular valves, valve insufficiency and myocardial dysfunction, which, in turn, become more common with the progression of the disease. According to the consensus of the American College of Veterinary Internal Medicine, endocardiosis can be classified into stages, according to its clinical evolution. The objective of the present study was to determine the clinical, electrocardiographic, radiographic and echocardiographic profile of dogs with chronic degenerative mitral valve disease in a cardiology service between the years 2017 to 2022. The selected animals were those whose diagnoses involved valve alteration with association with echocardiographic evaluation. The data obtained were compiled in Microsoft Excel® spreadsheets and evaluated using descriptive statistics and Pearson's correlation using the BioEstat® software. Through the observations and results obtained, it was possible to relate that the hypothesis of the correlation between the severity of clinical signs and the exacerbation of the structural alteration of the heart valves may be indicators of a worse prognosis for the evolution of chronic degenerative mitral valve disease.

A doença valvar degenerativa crônica de mitral (DVDCM) é a cardiopatia adquirida mais comum e principal causa de insuficiência cardíaca congestiva (ICC) em cães de meia idade a idosos, sendo mais frequente em raças de pequeno porte e miniaturas, sendo rara nas raças de médio a grande porte. Essa doença é caracterizada pela deformidade nodular dos folhetos valvulares, assim como espessamento e, em alguns casos, distensão das cordas tendíneas. Os achados ecocardiográficos incluem cardiomegalia, espessamento das válvulas atrioventriculares, insuficiência valvar e disfunção miocárdica que, por sua vez, tornam-se mais comuns com a progressão da doença. De acordo com o consenso do American College of Veterinary Internal Medicine, a endocardiose pode ser classificada em estágios, de acordo com a sua evolução clínica. O objetivo do presente estudo foi determinar o perfil clínico, eletrocardiográfico, radiográfico e ecocardiográfico de cães portadores de doença valvar degenerativa crônica de mitral em um serviço de cardiologia entre os anos de 2017 a 2022. Os animais selecionados foram aqueles cujos diagnósticos envolveram alteração valvar com associação a avaliação ecocardiográfica. Os dados obtidos foram compilados em planilhas do programa Microsoft Excel® e avaliados por meio de estatística descritiva e correlação de Pearson utilizando o software BioEstat®. Por meio das observações e resultados obtidos, possibilitou-se relacionar que a hipótese da correlação entre gravidade dos sinais clínicos com a exacerbação da alteração estrutural das valvas cardíacas podem ser indicadores de prognóstico pior para a evolução da doença valvar degenerativa crônica de mitral.

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Cardiac rhythm disorders are diagnosed through electrocardiography, which is an important tool to investigate other systemic conditions that may be related to the cardiac conduction system. Cardiac regulation is controlled by the autonomic nervous system, and in dogs, it is mainly modulated by a parasympathetic action exerted by the vagus nerve, called vagal tone. Increased vagal tone can occur physiologically or pathologically, leading to the occurrence of bradyarrhythmias. However, some studies report that airway diseases can exacerbate this tone, together with the reduction of sympathetic pathway activities. This study aimed to analyze the cardiac rhythms in dogs presenting with electrocardiographic alterations related to respiratory diseases, in connection with the exacerbation of vagal tone. Medical records of animals whose diagnoses involved at least one respiratory condition and who underwent electrocardiographic assessment between March 2017 to March 2021 were compiled. Data obtained were compiled in Microsoft Excel®1 spreadsheets and evaluated using descriptive statistics through the BioEstat®2 software. Pearson's correlation was used for quantitative data. A correlation between autonomic regulation and vagal exacerbation was observed in cases with obstructive airways diseases.(AU)

Os distúrbios do ritmo cardíaco são diagnosticados por meio da eletrocardiografia, que é uma importante ferra-menta para investigar outras condições sistêmicas que podem estar relacionadas ao sistema de condução cardíaco. A regulação cardíaca é controlada pelo sistema nervoso autônomo e, em cães, é modulada principalmente pela ação parassimpática exer-cida pelo nervo vago, denominada tônus vagal. O aumento do tônus vagal pode ocorrer fisiologicamente ou patologicamente, levando à ocorrência de bradiarritmias. No entanto, alguns estudos relatam que as doenças das vias aéreas podem exacerbar esse tônus, juntamente com a redução das atividades das vias simpáticas. Este estudo teve como objetivo analisar os ritmos cardíacos em cães com alterações eletrocardiográficas relacionadas a doenças respiratórias, relacionadas à exacerbação do tônus vagal. Foram compilados os prontuários dos animais cujos diagnósticos envolvessem pelo menos uma condição respiratória e que realizaram avaliação eletrocardiográfica, no período entre março de 2017 a março de 2021. Os dados obtidos foram com-pilados em planilhas do Microsoft Excel®1 e avaliados por meio de estatística descritiva por meio do software BioEstat®2. A correlação de Pearson foi usada para dados quantitativos. Foi observada correlação entre regulação autonômica e exacerbação vagal em casos com doenças obstrutivas das vias aéreas.(AU)

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Background: Atrial ectopic rhythm is a type of supraventricular arrhythmia, originating in two distinct points in the atrialregion. In the electrocardiographic (ECG) tracing, it is represented by independent depolarizations of sinus P waves andectopic P waves. The occurrence of this disorder is rare, and the diagnosis criteria are the presence of the described waveswithin the basal rhythm. In humans, there have been reports related to severe heart failure with an unfavorable prognosis.The present report aimed to describe the clinical case of a dog with unilateral atrial ectopic rhythm without any underlying cardiac disorder.Case: A 8-year-old male golden retriever was brought to a veterinary clinic for a preoperative evaluation for lipoma removalin the right forelimb. On clinical examination, the owner stated that the patient was active, with no signs of easy fatigueor cough. The canine displayed normophagy, normodipsia, normoquezia, and normouria. On physical examination, hedemonstrated a lymphatic temperament with tachypnea. The temperature and capillary filling time were within the normalrange, with a normokinetic pulse. Cardiac auscultation revealed a mild grade I/VI murmur in mitral focus and an 80-bpmheart rate. Respiratory auscultation revealed the presence of harshy lung sounds. The cough reflex was positive; the Piparotetest, negative. The blood test showed no noticeable changes in blood count and serum biochemistry. Systemic systolicblood pressure was 120 mmHg. On radiographic examination, no evidence of heart or lung abnormalities were identified.After the clinical evaluation, an ECG examination was performed; a unilateral atrial ectopic rhythm was observed withdifferent frequencies between atrial and ventricular rhythm and with P (164°) and P waves (80°). On echocardiographic...

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Presently, pet life expectancy is becoming longer and several diseases inherent to age have been diagnosed, with heart disease being a frequent finding. Although various heart diseases have different pathophysiologies, many morphological and hemodynamic changes can predispose patients to arrhythmias. The presence of arrhythmias can worsen the underlying heart disease and predispose patients to develop new alterations, making arrhythmia detection important for establishing adequate therapeutic protocols and a better prognosis. The present study aimed to determine the arrhythmias most frequently found in dogs treated at the Cardiology and Respiratory Diseases Service (SCDR) of the Small Animals Sector of the Veterinary Hospital of the Federal Rural University of Rio de Janeiro (UFRRJ), during the period from January to 2014 to December 2017, relating them to sex, age group, size, and the presence or absence of heart disease. A total of 586 medical records of dogs treated with SCDR-UFRRJ were retrospectively evaluated. Of these, 15.4% had arrhythmias, 95.6% had diagnoses of heart disease, 61.1% (55/90) were diagnosed with mitral valve disease, and 27.8% (25/90) had dilated cardiomyopathies. The most frequent rhythm disturbances were premature ventricular complexes associated with chronic degenerative mitral valve disease or dilated cardiomyopathy. Statistical analysis confirmed the risk of a cardiac patient developing rhythm or conduction alterations (OR, 4.46; p = 0.0003). In conclusion, the pathophysiology of heart failure can lead to the development of rhythm and conduction disorders.

Com a maior expectativa de vida dos animais de estimação, diversas enfermidades inerentes a idade têm sido diagnosticadas, sendo as cardiopatias um achado frequente. Apesar das diferentes cardiopatias terem fisiopatologias distintas, diversas alterações morfológicas e hemodinâmicas podem ocorrer predispondo ao aparecimento de arritmias. A presença de arritmias pode agravar a doença cardíaca de base e predispor ao desenvolvimento de novas alterações, tornando-se importante a sua detecção para instituição de protocolos terapêuticos adequados e melhor prognóstico da doença. O presente estudo teve como objetivo determinar as arritmias mais frequentemente encontradas em cães atendidos no Serviço de Cardiologia e Doenças Respiratórias (SCDR) do Setor de Pequenos Animais do Hospital Veterinário da Universidade Federal Rural do Rio de Janeiro (UFRRJ), no período de janeiro de 2014 a dezembro de 2017, relacionando-as com sexo, faixa etária, porte e presença ou não de cardiopatias. De maneira retrospectiva, foram avaliados 586 prontuários de cães atendidos no SCDR-UFRRJ. Destes, 15.4% apresentavam alguma arritmia e 95,6% apresentavam diagnostico de alguma cardiopatia, sendo 61.1% (55/90) diagnosticados com endocardiose de mitral e 27.8% (25/90) com cardiomiopatia dilatada. O distúrbio de ritmo mais frequente foram os complexos ventriculares prematuros associados a doença valvar degenerativa crônica de mitral ou a cardiomiopatia dilatada. Na análise estatística, o risco de um paciente cardiopata desenvolver alterações de ritmo ou de condução foi confirmado (OR: 4,46; p=0,0003). Conclui-se que a fisiopatologia da insuficiência cardíaca pode levar ao desenvolvimento de distúrbios de ritmo e também distúrbios de condução.

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The application of hydrotherapy is growing in the field of animal rehabilitation to improve strength, endurance, fitness, and range of motion, in addition to reducing pain. In the same way, land-based activity is recommended for various conditions, including hypertension, muscle atrophy, and obesity. There is a lack of studies that evaluate the safety of incremental exercise in American Pit Bull Terriers. This study assessed the influence of activity on underwater and dry land treadmills on the physiological parameters of dogs. In this regard, 12 adult, male, healthy, and untrained American Pit Bull Terriers were subjected to an incremental exercise test (IET) on the underwater treadmill (Group I) and the dry land treadmill (Group II). Heart rate (HR), respiratory rate (RR), rectal temperature (RT), systolic blood pressure (SBP), and electrocardiographic evaluation, were evaluated before activity (T0), immediately after (T1), 30 min after (T2), and 90 min after the end of exercise (T3), and plasmatic lactate concentrations were measured at T0, T1, and T2 time points. Results obtained were submitted to the Shapiro-Wilk test, ANOVA and Tukey's test, considering P<0.05. Water activity induced a reduction in RR (P=0.00674) in all examinations after the test on the underwater treadmill and proved to be more demanding than activity on the land treadmill, considering the presence of a deeper and slower RR. Exercise sessions in both groups did not elevate the lactate concentration. The IET can be performed safely on an underwater or dry land treadmill in healthy American Pit Bulls.

A hidroterapia apresenta crescente aplicação no ramo da reabilitação animal, com o intuito de aumentar a força, resistência muscular e amplitude de movimento articular, além de reduzir a dor e melhorar o condicionamento físico do paciente. Assim como a hidroterapia, a atividade desenvolvida em solo é indicada para diversas afecções, inclusive para pacientes hipertensos, com atrofia muscular ou com sobrepeso. São escassos os estudos que avaliam a segurança de testes incrementais em esteira aquática e em esteira seca em American Pit Bull Terriers. Este estudo teve como objetivo avaliar os efeitos da atividade em esteira aquática e em esteira seca sobre os parâmetros fisiológicos de cães. Para isto, cães da raça American Pit Bull Terrier (n=12) machos, adultos, saudáveis e não treinados foram submetidos a teste de esforço incremental (TEI) em hidroesteira com água (Grupo I) e sem água (Grupo II). A frequência cardíaca (FR), frequência respiratória (FR), temperatura retal (TR), pressão arterial sistólica (PAS) e avaliação eletrocardiográfica, foram aferidas antes da atividade (T0), imediatamente após (T1), 30 minutos após (T2) e 90 minutos após o exercício (T3), e a concentração plasmática de lactato foi dosada nos momentos T0, T1 e T2. Os resultados foram submetidos ao teste de Shapiro-Wilk, análise de variância (ANOVA) e pelo Teste de Tukey, considerando significativo o valor de P < 0.05. Houve diminuição da frequência respiratória (P = 0,00674) após a atividade em esteira aquática, que se mostrou mais exigente que a atividade em esteira terrestre, considerando a apresentação de padrão respiratório mais lento e profundo. As sessões de exercício em ambos os grupos não elevaram a concentração de lactato. O teste de esforço incremental em esteira aquática, ou em esteira seca, pode ser desenvolvido com segurança por cães American Pit Bull saudáveis.

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Digoxin is a cardiotonic glycoside that is traditionally used for the treatment of heart failure and atrial fibrillation in humans and animals. However, the use of digoxin is still a challenge in clinical practice due to its narrow therapeutic range and its potential interaction with several drugs, which could facilitate the development of toxicity. A 12-year-old Labrador retriever was referred with a clinical diagnosis of heart failure and atrial fibrillation, anorexia, vomiting, and diarrhea. He had been medicated with digoxin, furosemide, lisinopril, and amiodarone. The patient also showed clinical signs of hip osteoarthritis and received firocoxib for four days. He additionally received drugs for gastrointeritis. The electrocardiogram demonstrated atrial fibrillation and signs of digitalis toxicity. Laboratory examination showed a high concentration of plasma digoxin, and 5 days after withdrawal of the drugs, the symptoms disappeared, as did the digitalis effects seen in the previous electrocardiogram.(AU)

A digoxina é um glicosídeo cardiotônico tradicionalmente utilizado no tratamento de insuficiência cardíaca e fibri-lação atrial em humanos e animais. Porém, o uso da digoxina continua sendo um desafio na prática clínica devido a sua estreita faixa terapêutica, bem como a sua potencial interação com diversos fármacos, facilitando o desenvolvimento de toxicidade. Um Labrador Retriever de 12 anos de idade foi encaminhado com diagnóstico clinico de insuficiência cardíaca, apresentando fibrilação atrial, anorexia, vômitos e diarreia. Ele vinha sendo medicado com digoxina, furosemida, lisinopril e amiodarona. Ele havia sido concomitantemente medicado com firocoxibe por quatro dias para tratamento de osteoartrite coxo-femoral, além de medicamentos para gastroenterite. O eletrocardiograma demonstrou fibrilação atrial e sinais de toxicidade digitalica. O exame laboratorial revelou alta concentração de digoxina plasmática sendo que, cinco dias após a suspensão dos medica-mentos, o paciente já apresentava melhora clinica acentuada, enquanto os efeitos digitálicos observados no eletrocardiograma anterior desapareceram.(AU)

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Resynchronization protocols have been proposed as a way of shortening females' unproductive time in the flock, with good results in cattle and sheep. In goats, initial studies have shown that a second progestogen device inserted before luteolysis and pregnancy diagnosis does not interfere with the corpus luteum lifespan or functionality. This study aimed to evaluate the follicular growth, ovulation pattern and pregnancy rate after insertion of a second and new progestogen device for resynchronizing, with or without equine Chorionic Gonadotrophin (eCG), submitted to natural mating (NM) or artificial insemination (AI) to propose a viable resynchronization protocol for dairy goats. A total of 38 multiparous Saanen goats underwent a short-term progesterone protocol [six days exposed to medroxyprogesterone acetate (MAP) intravaginal sponges + 200 IU eCG and 0.12 mg of cloprostenol sodium on the 5th day + 0.025 mg of lecirelin 34 hours after sponge withdrawal] and, on day 16th after the ovulation, received a new MAP device which was retained until day 21. At this moment females were split into four groups: GeCG+NM ­ 100 IU eCG with NM; GSal+NM ­ saline solution with NM; GeCG+AI ­ 100 IU eCG with AI; and GSal+AI ­ saline solution with AI. Ultrasound scans were performed every 12 h from sponge withdrawal (day 21) until 108 h after sponge withdrawal (day 25) for follicular dynamics evaluation, at 240 h (day 31) for assessing the presence of active corpus luteum, and on day 60 for pregnancy diagnosis. No differences were found regarding ovulation time, synchronization and follicle size. However, GeCG+NM presented a greater estrus manifestation rate (100%) and pregnancy rate (62.5%) when compared to GSal+AI. In conclusion, resynchronization protocols in dairy goats may present satisfactory results.(AU)

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The present study aimed to identify and describe cardiac alterations in sheep experimentally poisoned with Palicourea marcgravii through analysis of serum cardiac biomarkers (serum troponin I and creatine kinase - CK-MB) and electro and echocardiographic assessments to contribute to a better understanding of the poisoning pathophysiology. P. marcgravii is the main plant within a group of 22 species that cause sudden death in Brazil; its toxic principle is sodium monofluoroacetate. Eight healthy crossbreed male sheep, aged between five and twelve months, weighing 14 to 27kg, were evaluated. The animals received 1g kg-1 of P. marcgravii plants orally. The sheep were evaluated before administering the plant (T0) through electro and echocardiography and blood collection to assess cardiac biomarkers (CK-MB and cTnI). Collections and analyses were repeated every four hours until the animal's death. During the study, there was the presence of extravasation of serum troponin I carried out in a qualitative test, with positive values at time T4, and the serum CK-MB biomarker had a peak at T4 and slightly decreased at T8. The electro and echocardiographic examinations showed that the cause of death in these animals was due to acute heart failure characterized by arrhythmias, tachycardia/ventricular fibrillation, drop in cardiac output, left ventricular (LV) systolic dysfunction by the progressive decrease in the LV ejection fraction (EF), decrease in LV fractional shortening (FS), and decrease in aortic flow velocity and aortic flow gradient. This study seems to be the first to evaluate cardiac alterations in sheep poisoned by P. marcgravii through cardiac biomarkers and electro and echocardiographic exams.

O presente estudo objetivou identificar e descrever as alterações cardíacas de ovinos intoxicados experimentalmente por Palicourea marcgravii através das análises de biomarcadores cardíacos séricos (troponina I sérica e a creatinoquinase - MB) e das avaliações eletro e ecocardiográficas contribuindo para o melhor entendimento da fisiopatologia da intoxicação. Palicourea marcgravii é a principal planta dentro de um grupo de 22 espécies que causam "morte súbita" no Brasil e seu princípio tóxico é o monofluoracetato de sódio. Foram utilizados oito ovinos saudáveis machos, sem raça definida, com idades entre cinco e doze meses e peso de 14 a 27kg. Os animais receberam 1g/kg de Palicourea marcgravii por via oral. Os ovinos foram avaliados momentos antes da administração da planta (T0) através de eletro e ecocardiograma e coleta de sangue para avaliação dos biomarcadores cardíacos (CK-MB e cTnI). As análises e coletas foram repetidas a cada quatro horas até o óbito do animal. Durante o estudo observou-se extravasamento de troponina I sérica realizada em teste qualitativo, com valores positivos já em T4, assim como o biomarcador CK-MB sérico teve seu pico de aumento em T4 e em T8 houve uma leve redução. Aos exames eletro e ecocardiográfico foi possível determinar que a causa do óbito nestes animais ocorreu devido à insuficiência cardíaca aguda caracterizada por arritmias, taquicardia/fibrilação ventricular, queda no débito cardíaco, disfunção sistólica do ventrículo esquerdo (VE) pela diminuição progressiva da fração de ejeção (EF) do VE, diminuição na fração de encurtamento (FS) do VE, diminuição da velocidade do fluxo aórtico e do gradiente do fluxo aórtico. Este é o primeiro estudo que avalia as alterações cardiológicas de ovinos intoxicados por P. marcgravii através de biomarcadores cardíacos e exames eletro e ecocardiográficos.

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O eletrocardiograma (ECG) é um importante método diagnóstico, essencial para determinar o ritmo e o funcionamento elétrico do coração. Os gambás (D. albiventris) frequentemente são atendidos nos Centros de Triagem de Animais Silvestres (CETAS), contudo pouco se sabe sobre o sistema cardiovascular dessa espécie. Dessa forma, o objetivo foi estabelecer valores de referência dos parâmetros eletrocardiográficos dessa espécie. Foram utilizados 32 filhotes, considerados hígidos nos exames clínicos geral e específico. Avaliaram-se a frequência cardíaca, o ritmo, a morfologia, a amplitude e a duração das ondas P, o complexo QRS e T, a duração dos intervalos PR e QT e o segmento ST. A frequência cardíaca média foi de 214 batimentos por minuto (bpm), o ritmo sinusal mostrou-se normal e houve arritmia sinusal em 25% dos pacientes. O eixo médio foi de 40º(QRS)e 47º (P). A onda P apresentou morfologia positiva (81,3%) e negativa (18,7%), amplitude de 0,03mV (±0,01) e duração de 0,04s (±0,04). O complexo QRS apresentou morfologia QRS ou RS (31%) e duração de 0,05s (±0,06). A amplitude de Q foi de -0,04mV (±0,05), a de R foi 0,23mV (±0,16) e S -0,07mV (±0,08). Já a onda T apresentou morfologia variada, amplitude de 0,04mV (±0,04) e duração de 0,04s (±0,09). O intervalo PR obteve duração de 0,05s (±0,08), QT com intervalo entre 0,08 e 0,21 e o segmento ST médio de 0,05s (±0,02). Dessa forma, observou-se que foi possível realizar o ECG em gambás filhotes e que o sexo e o peso não influenciaram no traçado obtido. Os resultados diferiram de cães, gatos e de outras espécies de gambás.

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Background: During pregnancy, cardiovascular adaptations occur in order to meet maternal demands and adequate supportfor fetal development, but they are still unclear in the equine species, especially in the American Miniature horse breed.The main hemodynamic changes that occur during pregnancy are increased heart rate, cardiac output, and blood volume.It is necessary to use the reference values for the miniature breeds, in addition to the age range and reproductive condition,so the objective of this study was to evaluate the effect of pregnancy on electrocardiographic (ECG) parameters in maresand also of age in newborns foals of American Miniature horse breed.Materials, Methods & Results: Ten American Miniature Horse mares, between 7 and 19 years old (12.14 ± 4.05 years),116.85 ± 24.09 kg of body weight were used in the experiment. All these mares were pluriparous, with 5.9 ± 3.5 of births,minimum of 2, and maximum of 12 foaling times. They were maintained in common social group in an indoor house stablewith straw bed, with access to an outdoor paddock for several h per day. Twice a day they were fed with hay. Mineral supplements and water were available ad libitum. The ECG were obtained in 10 pregnant mares and in 10 neonates. All femaleswere examined at a representative time of each trimester of pregnancy, at 30, 210, 300 days before and 21 days after delivery.Neonates were examined on different times: first 24 h after delivery, weekly on the 7th, 14th, 21st, 28th and 35th days of age.The ECG parameters considered were the heart rate and rhythm, duration and intervals (P, PR, QRS, QT, T) and amplitude(P, R, S, T) of ECG waves. The mean of pregnancy duration was 319.4 ± 4.97 days. Heart Rate (HR) varied between 51 to59 bpm during pregnancy and 56 bpm on the 21st day after delivery. Comparing the clinical parameters of pregnant mares,non-pregnant mares and foal a difference was found for HR, Respiration Rate (RR) and...

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Background: The hooded capuchin that occurs in the Brazilian states of Mato Grosso and Mato Grosso do Sul belongs tothe species Sapajus cay. This robust species of capuchin monkey is characterized by its highly varied diet. Although it is welladapted to the natural environment, the survival of this species has come under increasing threat. In fact, several animals havebeen rescued and taken into veterinary medical care, where its correct capture and restraint minimize the occurrence of adverseeffects to the animal and to veterinary anesthesiologists. This paper reports on the emergency care of a hooded capuchin (S.cay) rescued by the Environmental Police of the state of Mato Grosso do Sul, Brazil, and sent to veterinary medical care.Case: An adult female hooded capuchin, weighing 1.6 kg, was subjected to veterinary care to treat trauma probably causedby being run over. The animal exhibited intense prostration, 10% dehydration, pale and slightly jaundiced oral and ocularmucous membranes, impaired consciousness, cachexia, muscle weakness, sarcopenia, a probable fracture in the proximalportion of the left tibia and a laceration and possible fracture of the right metatarsus. The patient was stabilized by subjectingher to fluid therapy with Ringer’s lactate solution supplemented with glucose and vitamins. The animal was anesthetizedwith an intramuscular injection of 11 mg/kg ketamine and 0.6 mg/kg midazolam, and blood count, serum biochemistryand electrocardiography were performed. Blood tests revealed hypochromic microcytic anemia, liver disease and a slightincrease in urea to 56 mg/dL (reference: 14.4-48.9 mg/dL). The electrocardiogram revealed the following: HR: 260b.p.m; P axis: -115.36º; QRS axis: 50.17º; T duration: 36 ms; R amplitude: 0.68 mV; P amplitude: 0.17 mV; P duration:...

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The objective of this study was to describe the prevalence, survival time, and risk factors of myxomatous mitral valve disease (MMVD) in dogs by a retrospective observational cohort study design of a Brazilian veterinary center, admitted from 2012 to 2018 (2.585 days). Considering the 105 dog files confirmed as MMVD, the prevalence of the disease was higher in small-breed dogs with ages from 10 to 19 years (30.3%). The survival time of the dogs at B1 stage (1.854 ± 145 days) was higher than the B2 (1.508+209) and C/D (930 ± 209). Higher risks of death (hazard ratio) were detected in the presence of syncope (2.5), pulmonary crackling (2.0), dyspnea (1.9), and higher values of vertebral heart scale (1.7), radiographic left atrium dimension (1.8), the ACVIM staging (1.7), and the duration of QRS complex (1.05). The results achieved demonstrated higher prevalence of MMVD in old small-breed dogs, associated with longer survival time in the B1 stage of the disease, and higher risk of death related to the presence of clinical signs, such as dyspnea, syncope, and pulmonary crackling, beyond some radiographic, echocardiographic, and electrocardiographic variables of heart or atrial enlargement.(AU)

O objetivo deste estudo foi descrever a prevalência, o tempo de sobrevivência e os fatores de risco da doença mixomatosa valvar mitral (DMVM) em cães, por meio de estudo de coorte observacional retrospectivo, os quais foram atendidos em um centro veterinário de 2012 a 2018 (2.585 dias). Considerando os 105 arquivos de cães com confirmação da DMVM, maior prevalência foi observada em raças pequenas com idades entre 10 e 19 anos (30,3%). O tempo de sobrevivência de cães em estágio B1 (1.854+145 dias) foi superior ao B2 (1.508+209) e ao C/D (930+209). Maior risco de morte (hazard ratio) foi observado na presença de síncope (2,5), crepitação pulmonar (2,0), dispneia (1,9), bem como de valores superiores de VHS (1,7), dimensão radiográfica do átrio esquerdo (1,8), estadiamento ACVIM (1,7) e duração do complexo QRS (1,05). Os resultados obtidos demonstraram maior prevalência de DMVM em cães idosos de raças pequenas, associada a maior tempo de sobrevida no estágio B1 da doença e a maior risco de morte relacionado à presença de sinais clínicos como dispneia, síncope e crepitação pulmonar, além de algumas variáveis radiográficas, ecocardiográficas e eletrocardiográficas de cardiomegalia ou aumento atrial esquerdo.(AU)

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The Bradypus variegatus species presents peculiar anatomophysiological properties and many aspects of its organic systems still need to be clarified, especially regarding the cardiovascular system, given its participation in vital activities. Disorderly anthropic action has had drastic consequences in sloth populations and the need to treat sick and injured animals is increasingly common. To this end, the importance of knowing its characteristics is emphasized. Therefore, this study proposed to describe the internal macroscopic structures of the sloth's heart, as well as to measure the ventricular walls and indicate the electrical activity of the organ. For the dissections, 15 Bradypus variegatus cadavers were used (1 young female, 9 adults females and 5 adult males) belonging to the Área de Anatomia of the Departamento de Morfologia e Fisiologia Animal (DMFA), Universidade Federal Rural de Pernambuco (UFRPE), Recide, PE, Brazil. After they were fixed and preserved, the specimens received a midsagittal incision in the chest, followed by soft tissue folding and removal of ribs to access the heart. The organ was derived from the cavity and sectioned sagittal medially to identify its internal anatomy. Ventricular walls and interventricular septum were measured with a steel caliper (150 mm / 0.02 mm). An electrocardiogram was performed to determine the electrical profile on 5 healthy B. variegatus sloths, living under semi-livestock conditions at the Recife Zoo, PE, Brazil. The electrodes were taken from the regions, scapular and glutes of the animals that were called hugging a keeper during the procedure, carried out in the Zoo itself, using a portable device. Based on the data obtained, sloths have cardiac chambers separated by septa, however between atria and ventricles, in both antimeres, there are atrioventricular ostia, where valves are found, consisting of 3 valves on the right and 2 on the left. The atria are practically smooth inside and have their cavity enlarged by the atria, the right being larger than the left, these having a greater amount of pectineal muscles in relation to the atria. The ventricles have trabeculae and papillary muscles, 3 on the right and 2 on the left. These muscles hold the tendinous chords that connect the valves. The existence of trabeculae marginal septum was not evidenced. The thickness of the wall of the left ventricle, as well as that of the interventricular septum, proved to be greater than the thickness of the wall of the right ventricle, regardless of the age or sex of the animals. Based on the electrocardiographic recordings, the sloths presented sinus rhythm, with a heart rate between 67 and 100 bpm. The electrical axis ranged from -60º to -90º. The P wave is smoother than the QRS complex. While the S-T segment was classified as isoelectric. The T wave was shown to be + and predominantly > or = at 25% of the S wave, which characterized an rS type QRS deflection in both females and males. The general characteristics of the cardiac chambers in sloths are similar to those observe in other domestic and wild mammals. However, the presence of pectineal muscles associated with the atria and auricles differs from that observed in mammals such as the paca and raccoon and in birds such as the ostrich, which have trabecular structures in these cavities. The number of valves in sloths is equal to the anteater. However, it has a marginal trabeculae septum, not seen in Bradypus variegatus. According to the electrocardiographic findings, the rhythm was sinus, but much lower than that observed in the capuchin monkey, which also maintains arboreal habits.(AU)