Estudo anatômico das lesões de endocardiose em cães, prevalência e epidemiologia / Anatomical study of endocardiosis lesions in dogs, prevalence and epidemiology / Estudio anatómico de las lesiones de endocardiosis en el perro, prevalencia y epidemiología

O coração é composto por duas importantes valvas átrio-ventriculares, a tricúspide e a bicúspide ou mitral. As válvulas cardíacas asseguram o sentido do fluxo sanguíneo dos átrios para os ventrículos e destes para as artérias. A endocardiose é um processo degenerativo crônico progressivo das válvulas, que acomete especialmente os cães, denominada endocardiose ou "doença do cão velho". Embora qualquer das válvulas possa ser afetada, é a válvula mitral que é habitualmente envolvida, isoladamente ou em combinação com a válvula tricúspide. A sua prevalência tem sido associada a parâmetros como idade, sexo e raça, afetando especialmente animais adultos de raças de pequeno porte. A etiologia da endocardiose é desconhecida, mas parece haver uma base hereditária. As lesões macroscópicas iniciais consistem em pequenos nódulos nas margens livres da valva, ficando distorcidas e com suas dimensões reduzidas, mas significativamente espessas e de coloração opaca, branca ou reluzente. Microscopicamente, a endocardiose é vista como um processo degenerativo do tecido valvular com discreta infiltração de tecido conjuntivo fibroso. Em estágios iniciais a doença apresenta, à auscultação, murmúrios cardíacos de baixa intensidade, sem sinais de descompensação e é geralmente achado incidental durante a rotina de exame clínico. As cúspides fundem-se em sua inserção, mas separam-se em direção ao centro da abertura, ajustando-se estreitamente ao mesmo tempo quando a valva se fecha e suas bordas livres são espessas e irregulares, especialmente durante uma fase tardia da vida. Com isso, o objetivo do presente trabalho foi averiguar as principais lesões, a epidemiologia e o grau de prevalência da endocardiose em cães na região noroeste do estado do Rio Grande do Sul, o que se verificou que não há casos frequentes na rotina clínica de pequenos animais de endocardiose. Não sendo possível verificar se há um sexo mais predisposto a apresentar a endocardiose. As lesões observadas na macroscopia eram referentes a nódulos brilhantes, e na microscopia presença de colágeno causando o espessamento da cúspide, além de achados inflamatórios.(AU)

The heart is composed of two important atrio-ventricular valves, the tricuspid and the bicuspid or mitral valve. The heart valves ensure the direction of blood flow from the atria to the ventricles and from the ventricles to the arteries. Endocardiosis is a chronic progressive degenerative process of the valves that affects dogs in particular, called endocardiosis or "old dog's disease". Although any of the valves can be affected, it is the mitral valve that is usually involved, either alone or in combination with the tricuspid valve. Its prevalence has been associated with parameters such as age, sex, and breed, affecting especially adult animals of small breeds. The etiology of endocardiosis is unknown, but there appears to be a hereditary basis. The initial macroscopic lesions consist of small nodules on the free margins of the valve, becoming distorted and reduced in size, but significantly thickened and opaque, white or shiny in color. Microscopically, endocardiosis is seen as a degenerative process of the valvular tissue with a discrete infiltration of fibrous connective tissue. In early stages the disease presents, on auscultation, with low-intensity cardiac murmurs without signs of decompensation and is usually an incidental finding during routine clinical examination. The leaflets fuse at their insertion, but separate towards the center of the opening, fitting closely together when the valve closes, and their free edges are thick and irregular, especially during a late phase of life. Thus, the aim of this study was to investigate the main lesions, the epidemiology and the degree of prevalence of endocardiosis in dogs in the northwest region of the state of Rio Grande do Sul, which was found that there are no frequent cases in the clinical routine of small animals of endocardiosis. It was not possible to verify whether there is a sex more predisposed to present endocardiosis. The lesions observed at macroscopy were referring to bright nodules, and at microscopy the presence of collagen causing thickening of the leaflet, besides inflammatory findings.(AU)

El corazón está compuesto por dos importantes válvulas aurículo- ventriculares, la tricúspide y la bicúspide o válvula mitral. Las válvulas cardíacas aseguran la dirección del flujo sanguíneo de las aurículas a los ventrículos y de los ventrículos a las arterias. La endocardiosis es un proceso degenerativo crónico y progresivo de las válvulas que afecta sobre todo a los perros, denominado endocardiosis o "enfermedad del perro viejo". Aunque cualquiera de las válvulas puede verse afectada, es la válvula mitral la que suele estar implicada, ya sea sola o en combinación con la válvula tricúspide. Su prevalencia se ha asociado a parámetros como la edad, el sexo y la raza, afectando especialmente a animales adultos de razas pequeñas. La etiología de la endocardiosis es desconocida, pero parece tener una base hereditaria. Las lesiones macroscópicas iniciales consisten en pequeños nódulos en los márgenes libres de la válvula, que se distorsionan y reducen de tamaño, pero se engrosan significativamente y adquieren un color opaco, blanco o brillante. Microscópicamente, la endocardiosis se observa como un proceso degenerativo del tejido valvular con una discreta infiltración de tejido conectivo fibroso. En fases tempranas, la enfermedad se presenta, en la auscultación, con soplos cardíacos de baja intensidad sin signos de descompensación y suele ser un hallazgo incidental durante el examen clínico rutinario. Las valvas se fusionan en su inserción, pero se separan hacia el centro de la apertura, encajando estrechamente cuando la válvula se cierra, y sus bordes libres son gruesos e irregulares, especialmente durante una fase tardía de la vida. Por lo tanto, el objetivo de este estudio fue investigar las principales lesiones, la epidemiología y el grado de prevalencia de endocardiosis en perros de la región noroeste del estado de Rio Grande do Sul, que se encontró que no hay casos frecuentes en la rutina clínica de pequeños animales de endocardiosis. No fue posible verificar si existe un sexo más predispuesto a presentar endocardiosis. Las lesiones observadas en la macroscopia fueron referentes a nódulos brillantes, y en la microscopia la presencia de colágeno causando engrosamiento de la valva, además de hallazgos inflamatorios.(AU)

Unilateral atrial ectopic rhythm in a golden retriever

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...

Unilateral atrial ectopic rhythm in a golden retriever

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...(AU)

Anatomia macroscópica interna e avaliação elétrica do coração de Bradypus variegatus / Internal macroscopic anatomy and electrical evaluation of the Bradypus variegatus heart

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)

Description of the female and larval stage of Denopelopia amicitia Dantas, Hamada & Mendes (Diptera: Chironomidae) / Descrição da fêmea e do estágio larval de Denopelopia amicitia Dantas, Hamada & Mendes (Diptera: Chironomidae)

Denopelopia amicitia Dantas, Hamada & Mendes was described based on the male and pupae collected in the Brazilian Amazon. Here we describe and illustrate the female and larva of this species. At both stages, D. amicitia is similar to Denopelopia atria Roback & Rutter, which is the only species in the genus with all life stages known until now.(AU)

Denopelopia amicitia Dantas, Hamada & Mendes foi descrita com base no macho e na pupa coletados na Amazônia brasileira. Aqui descrevemos e ilustramos a fêmea e a larva desta espécie. Em ambos os estágios, D. amicitia é similar à Denopelopia atria Roback & Rutter, que é a única espécie do gênero com todos os estágios de vida conhecidos até agora.(AU)

Use of measurements from thoracic radiographs to identify high mean left atrium pressure in dogs with myxomatous mitral valve disease / Uso de medidas obtidas de radiografias torácicas em cães para identificar aumento da pressão média do átrio esquerdo na doença mixomatosa da valva mitral

The aim of this study was to estimate echocardiographic elevated mean left atrium pressure (MLAP) based on measurements from thoracic radiographs and to determine a cut-off value for each radiographic measurement that suggests a high MLAP. A retrospective cross-sectional study was performed to include cases admitted from January 2015 to December 2016. Thoracic radiographic examinations from 93 dogs with and without a high MLAP were included. Specific measurements were made from thoracic radiographs and compared with echocardiographic variables known to indicate high MLAP. This comparison was used to generate equations that allowed the estimation of echocardiographic surrogates from the radiographic measurements. The values indicative of high MLAP were obtained using a regression curve. Formulas that indicated high MLAP were generated using a number of radiographic measurements. Positive echocardiographic findings of high MLAP were used as the gold standard. These formulas helped to predict high MLAP in myxomatous mitral valve disease (MMVD) without the need for echocardiographic examination. The best formula was left atrium (LA):aorta (Ao)echo = 0.03×(vertebral heart score,VHS) + 0.14×(LA) + 0.27×(LA:caudal vena cava (CVC)rad). Values ≥ 12.2v for VHS, ≥ 4.5cm for LA, ≥ 3.3 for LA:Ao rad and ≥ 3.2 for LA:CVC rad suggested high MLAP. Thus, we propose equations, based on measurements from thoracic radiographs, to identify high MLAP. Simple radiographic thoracic measurements, such as LA:CVCrad, can be used to define overload and a high MLAP in dogs with MMVD.(AU)

O objetivo desse estudo foi estimar o aumento da pressão média do átrio esquerdo (PMAE) na ecocardiografia usando equações baseadas em medidas obtidas das radiografias torácicas e determinar um valor de corte para cada uma dessas variáveis radiográficas. Foi realizado um estudo retrospectivo, observacional e transversal de casos atendidos de janeiro de 2015 a dezembro de 2016. Foram selecionados 93 exames radiográficos do tórax de cães, com ou sem aumento da PMAE. As medidas especificas foram feitas de radiografias torácicas e comparadas com variáveis ecocardiográficas que podem indicar um aumento da PMAE. Foi gerado equações que estimam medidas ecocardiográficas a partir das variáveis radiográficas. Os valores que indicam aumento da PMAE foram obtidos por meio das curvas de regressão. Foram usadas como "padrão ouro" as medidas ecocardiográficas que indicam aumento da PMAE. As fórmulas ajudam a predizer o aumento da PMAE em cães com doença mixomatosa da valva mitral (DMVM) sem a necessidade do exame ecocardiográfico. A melhor fórmula obtida foi: Átrio Esquerdo (AE):Aorta (Ao)eco=0.03×(VHS)+0.14×(AE)+0.27×(AE:Veia Cava Caudal (VCC)rad). Os valores ≥ 12.2 para VHS, ≥ 4.5cm para AE; ≥ 3.3 para AE:Ao rad e ≥ 3.2 para AE:VCC rad sugerem um aumento da PMAE. Essas equações, a partir de medidas radiográficas torácicas, auxilia na identificação do aumento da PMAE. Algumas medidas radiográficas simples, como a AE:VCC rad pode ser usada para definir sobrecarga e aumento da PMAE em cães com DMVM.(AU)

Age, sex and body weight related echocardiographic parameters of clinically healthy New Zealand white rabbits

Background: Echocardiography provides useful additional information on cardiac dimensions including heart wall anddimension of the ventricles, atria and conditions. Rabbits have been diagnosed with cardiac diseases, and an understandingof the animals’ cardiac chamber dimensions is vital in assessing the diseases’ severity and prognoses. Changes in cardiacdimensions due to age related and body weight were determined at different animals. The increased incidence of congenitalcardiovascular anomalies makes it essential to establish the diagnosis at an early age. The aims of this study 1) establishnormal values for the commonly used two-dimensional (2D) M-mode parameters using pre anaesthetics and 2) evaluatethe effects of age, sex, and body weight on echocardiographic parameters in clinically healthy New Zealand rabbits.Materials, Methods & Results: In this study we used 49 New Zealand white rabbits (25 male, 24 female) all reared under the same conditions. A general physical and clinical examination including complete blood count was performed foreach animal. Body surface area was calculated as BSA= 0.00718 × Height 0.725 × Weight 0.425. Rabbits were sedated withmidazolam before echocardiographic examination was performed. Echocardiographic examination was performed using aDC 6-Vet® (Mindray, PRC) ultrasonographic device equipped with a micro-convex 8 MHz probe. Right parasternal shortaxis view, B-mode and two-dimensional guided M-mode parameters were measured. Echocardiographic measurementswere performed using leading-edge-to-leading-edge conventions outlined by the American Society of Echocardiography.Statistical analyses were employed using the SPSS 19.0 program. Sex had no significant effect on the measured echocardiographic parameters except in the case of interventricular septum thickness in diastole values of the three-month-oldrabbits. The increase in the left ventricular systolic and diastolic diameters...

Age, sex and body weight related echocardiographic parameters of clinically healthy New Zealand white rabbits

Background: Echocardiography provides useful additional information on cardiac dimensions including heart wall anddimension of the ventricles, atria and conditions. Rabbits have been diagnosed with cardiac diseases, and an understandingof the animals cardiac chamber dimensions is vital in assessing the diseases severity and prognoses. Changes in cardiacdimensions due to age related and body weight were determined at different animals. The increased incidence of congenitalcardiovascular anomalies makes it essential to establish the diagnosis at an early age. The aims of this study 1) establishnormal values for the commonly used two-dimensional (2D) M-mode parameters using pre anaesthetics and 2) evaluatethe effects of age, sex, and body weight on echocardiographic parameters in clinically healthy New Zealand rabbits.Materials, Methods & Results: In this study we used 49 New Zealand white rabbits (25 male, 24 female) all reared under the same conditions. A general physical and clinical examination including complete blood count was performed foreach animal. Body surface area was calculated as BSA= 0.00718 × Height 0.725 × Weight 0.425. Rabbits were sedated withmidazolam before echocardiographic examination was performed. Echocardiographic examination was performed using aDC 6-Vet® (Mindray, PRC) ultrasonographic device equipped with a micro-convex 8 MHz probe. Right parasternal shortaxis view, B-mode and two-dimensional guided M-mode parameters were measured. Echocardiographic measurementswere performed using leading-edge-to-leading-edge conventions outlined by the American Society of Echocardiography.Statistical analyses were employed using the SPSS 19.0 program. Sex had no significant effect on the measured echocardiographic parameters except in the case of interventricular septum thickness in diastole values of the three-month-oldrabbits. The increase in the left ventricular systolic and diastolic diameters...(AU)

Morphometric assessment of canine heart without macroscopically visible changes caused by cardiac disease / Avaliação morfométrica do coração canino sem alterações macroscópicas de doença cardíaca

The purpose of this study was to collect data on the cardiac morphometry of thirty adult male and female dogs without macroscopic changes indicative of heart disease, regardless of animal's body weight and score. The dogs were weighed, grouped according to their body weight, and necropsied for a macroscopic evaluation of their cardiac measurements. The data obtained were included in a database. The following cardiac measures were evaluated: vertical and horizontal axes, weight, volume, thickness of the right and left atria and ventricles, and horizontal and vertical axes of the atrial and ventricular chambers. The heart weight was found to represent 0.6 to 1.1% of the animal's body weight. No differences were found in cardiac size and weight as a function of sex. The ratio between the vertical and horizontal cardiac axes was 1.11. The left ventricle was found to be 1.6 to threefold thicker than the right ventricle. The results were considered standard for dogs and can be used for macroscopic evaluations of cardiac hypertrophy or dilation.

Avaliou-se morfometricamente o coração de 30 cães adultos, sem histórico de doença cardíaca, sem restrição quanto ao porte e escore corporal, encaminhados para exame necroscópico e que não apresentavam alterações macroscópicas. A maioria dos animais era sem raça definida, sendo 14 machos e 16 fêmeas. Observou-se correlação positiva do peso dos cães com o tamanho do coração, com a espessura das paredes dos ventrículos e átrios, assim como com a largura e o comprimento das câmaras. Ainda, não foi constatada correlação entre a espessura dos átrios direito e esquerdo e o peso dos animais. A relação entre o peso cardíaco e o peso corpóreo dos cães foi mensurada individualmente, obtendo-se que o peso do coração representa de 0,6% a 1,1% do peso corporal. Não foram observadas diferenças relacionadas ao sexo. Na avaliação do quociente de relação entre os eixos cardíacos vertical e horizontal obteve-se o índice de 1,11 +/- 0,21. Em relação à proporção da espessura muscular dos ventrículos esquerdo e direito, obteve-se espessura do ventrículo esquerdo 1,6 a três vezes maior que a do ventrículo direito. Os dados desta pesquisa contribuem na construção de tabelas com valores de referência das diferentes medidas cardíacas em cães.

Morphometric assessment of canine heart without macroscopically visible changes caused by cardiac disease / Avaliação morfométrica do coração canino sem alterações macroscópicas de doença cardíaca

The purpose of this study was to collect data on the cardiac morphometry of thirty adult male and female dogs without macroscopic changes indicative of heart disease, regardless of animal's body weight and score. The dogs were weighed, grouped according to their body weight, and necropsied for a macroscopic evaluation of their cardiac measurements. The data obtained were included in a database. The following cardiac measures were evaluated: vertical and horizontal axes, weight, volume, thickness of the right and left atria and ventricles, and horizontal and vertical axes of the atrial and ventricular chambers. The heart weight was found to represent 0.6 to 1.1% of the animal's body weight. No differences were found in cardiac size and weight as a function of sex. The ratio between the vertical and horizontal cardiac axes was 1.11. The left ventricle was found to be 1.6 to threefold thicker than the right ventricle. The results were considered standard for dogs and can be used for macroscopic evaluations of cardiac hypertrophy or dilation.(AU)

Avaliou-se morfometricamente o coração de 30 cães adultos, sem histórico de doença cardíaca, sem restrição quanto ao porte e escore corporal, encaminhados para exame necroscópico e que não apresentavam alterações macroscópicas. A maioria dos animais era sem raça definida, sendo 14 machos e 16 fêmeas. Observou-se correlação positiva do peso dos cães com o tamanho do coração, com a espessura das paredes dos ventrículos e átrios, assim como com a largura e o comprimento das câmaras. Ainda, não foi constatada correlação entre a espessura dos átrios direito e esquerdo e o peso dos animais. A relação entre o peso cardíaco e o peso corpóreo dos cães foi mensurada individualmente, obtendo-se que o peso do coração representa de 0,6% a 1,1% do peso corporal. Não foram observadas diferenças relacionadas ao sexo. Na avaliação do quociente de relação entre os eixos cardíacos vertical e horizontal obteve-se o índice de 1,11 +/- 0,21. Em relação à proporção da espessura muscular dos ventrículos esquerdo e direito, obteve-se espessura do ventrículo esquerdo 1,6 a três vezes maior que a do ventrículo direito. Os dados desta pesquisa contribuem na construção de tabelas com valores de referência das diferentes medidas cardíacas em cães.(AU)

P wave dispersion in obese dogs with and without mitral valve disease / Dispersão da onda P em cães obesos apresentando ou não doença valvar mitral

Pwave dispersion (Pd) is an electrocardiographic index defined as the difference between the minimum and maximum Pwave duration in multiple leads. The augmentation of Pd reflects the discontinuous and inhomogeneous atrial depolarization resulting from cardiac and non-cardiac conditions. In humans, an increased Pd is associated with the development of cardiac arrhythmias, particularly atrial fibrillation. To investigate Pd in obese dogs, we enrolled 76 dogs, which were classified in four distinct categories according to body condition and the existance of valve insufficiency: obese dogs (O), dogs with both obesity and cardiac disease (O+CD), lean dogs with cardiac disease (CD) and healthy controls (H). To be included in the study, all dogs underwent an electrocardiographic and echocardiographic assessment. We reported significantly higher Pd in the animals included in categories O, O+CD and CD (18.0±7.6ms, 16.1±4.4ms, 12.1±4.3ms, respectively) as compared to the healthy subjects (7.3±2.2ms). Also, significant correlations between Pd and both the body mass index and body fat percentage were documented for the obese dogs. However, no association between Pd and LA/Ao could be identified in patients belonging to the O, O+CD and H categories. Thus, we have demonstrated that obese dogs, regardless of their valvular competency status, present high Pd values, suggesting an impaired propagation of atrial electrical impulse.(AU)

A dispersão da onda P (Pd) é um índice eletrocardiográfico definido como a diferença entre as durações máxima e mínima da onda P em múltiplas derivações. O aumento da Pd reflete a despolarização discontínua e não homogênea resultante de condições cardíacas e não cardíacas. Em seres humanos, uma Pdaumentada está associada com o desenvolvimento de arritmias cardíacas, particularmente fibrilação atrial. Com o intuito de investigar a Pd em cães obesos, foram selecionados 76 cães, os quais foram classificados em quatro categorias distintas, de acordo com sua condição corporal e a existência de insuficiência valvar: cães obesos (O), cães com obesidade e doença cardíaca (O+CD), cães magros com doença cardíaca (CD) e cães saudáveis usados como controle (H). Uma vez selecionados para o estudo, todos os cães foram submetidos às avaliações eletrocardiográfica e ecocardiográfica. Os resultados mostraram maior Pd nos animais pertencentes aos grupos O, O+CD e CD (18.0±7.6ms, 16,1±4,4ms, 12,1±4,3ms, respectivamente) quando comparados aos cães saudáveis (7.3±2.2ms). Além disso, foram verificadas correlações significativas entre Pde tanto o índice de massa corporal quanto o percentual de gordura corporal nos cães obesos. Entretanto, não se identificou associação entre Pd e a relação AE/Ao nos pacientes das categorias O, O+CD e H. Dessa forma, foi possível demonstrar que cães obesos, independentemente do estado de competência valvar, apresentam Pd elevada, fato que sugere comprometimento da propagação do impulso elétrico atrial.(AU)

Use of total venous inflow occlusion to enable correction of an atrial septal defect in a dog

Background: Atrial septal defects are generally classified into three types: ostium secundum, ostium primum, and sinus venosus. Diagnose is normaly confirmed with Doppler echocardiography, which can identify and classify atrial septal defects types. This cardiac anomaly may be corrected by different surgical approaches, such as cardiopulmonary bypass or transvenous approaches. Therefore, we chose to close the atrial septal defect using a total venous inflow occlusion technique (TIVO), which has been successfully used in other procedures without major postoperative complications, and are notably cheaper and requires no specialized equipment, been able to be done in different places.Case: An American Pit Bull Terrier was referred to our surgical service for ostium secundum atrial septal defect correction, by the time of surgery the patient presented dyspneic; normal capillary refill time and rectal temperature; the owner mentioned the patient exhibited exercise intolerance and delayed development compared to other dogs of the same age or from the same litter. Cardiac auscultation revealed a systolic murmur at the left base, femoral pulse was normokinetic, and patient was emaciated and prostrated at the time of clinical evaluation. Atrial septal defect was suspected and then confirmed by Doppler echocardiography that revealed a discontinuous area in the interatrial septum, and by color doppler images an aliased signal, that extended through the interatrial septum and shunted from the left to the right atria, was visualized, confirming an ostium secundum atrial septal defect. After a right intercostal thoracotomy, a subphrenic pericardiectomy was performed to provide access to the heart. Cranial and caudal vena cava as well as the azygos vein, were dissected, which allowed placement of a Satinsky’s clamp to proceed with TIVO. Before TIVO initiation, a pursestring suture with 3-0 polypropylene was applied to the right atrium.[...]

Use of total venous inflow occlusion to enable correction of an atrial septal defect in a dog

Background: Atrial septal defects are generally classified into three types: ostium secundum, ostium primum, and sinus venosus. Diagnose is normaly confirmed with Doppler echocardiography, which can identify and classify atrial septal defects types. This cardiac anomaly may be corrected by different surgical approaches, such as cardiopulmonary bypass or transvenous approaches. Therefore, we chose to close the atrial septal defect using a total venous inflow occlusion technique (TIVO), which has been successfully used in other procedures without major postoperative complications, and are notably cheaper and requires no specialized equipment, been able to be done in different places.Case: An American Pit Bull Terrier was referred to our surgical service for ostium secundum atrial septal defect correction, by the time of surgery the patient presented dyspneic; normal capillary refill time and rectal temperature; the owner mentioned the patient exhibited exercise intolerance and delayed development compared to other dogs of the same age or from the same litter. Cardiac auscultation revealed a systolic murmur at the left base, femoral pulse was normokinetic, and patient was emaciated and prostrated at the time of clinical evaluation. Atrial septal defect was suspected and then confirmed by Doppler echocardiography that revealed a discontinuous area in the interatrial septum, and by color doppler images an aliased signal, that extended through the interatrial septum and shunted from the left to the right atria, was visualized, confirming an ostium secundum atrial septal defect. After a right intercostal thoracotomy, a subphrenic pericardiectomy was performed to provide access to the heart. Cranial and caudal vena cava as well as the azygos vein, were dissected, which allowed placement of a Satinskys clamp to proceed with TIVO. Before TIVO initiation, a pursestring suture with 3-0 polypropylene was applied to the right atrium.[...](AU)

Hemangiosarcoma at the base of the left atrium of a dog with mitral and tricuspid valve degeneration ­ case report / Hemangiossarcoma na base do átrio esquerdo de um cão com degeneração da válvula mitral e tricúspide ­ relato de caso

Hemangiosarcoma (HSA) is a malignant neoplasm originating from the vascular endothelium, with high metastatic power and commonly described in the spleen, liver, and right atrium. Thus, the objective of the present study is to report the occurrence of HSA at the base of the left atrium of a male, elderly, Lhasa Apso dog, treated with cyanosis, orthopedic position, cough. In the physical examination, the presence of crackling was observed in pulmonary lobes, murmur in focus of mitral and tricuspid grade IV\VI. The recommended emergency therapy was performed until the clinical improvement of the animal. After echocardiography, mitral and tricuspid valvular degeneration was confirmed, as well as the presence of an irregular, mixed echocardiogram, extra-cardiac, immobile at the base of the left atrium, measuring 2.9 x 1.44 cm in diameter. The clinical therapy established stabilized the clinical picture for 128 days, with recurrence of pulmonary edema and severe hemorrhagic pleural effusion, with the owners opting for euthanasia of the animal and necropsy confirming the definitive diagnosis of extrahepatic SAH at the base of the left atrium.(AU)

O hemangiossarcoma (HSA) é uma neoplasia maligna originada no endotélio vascular, com alto poder metastático e comumente descrito no baço, fígado e átrio direito. Assim, o objetivo deste trabalho é relatar a ocorrência do HSA na base do átrio esquerdo de um cão, macho, idoso, da raça Lhasa Apso, atendido apresentando cianose, posição ortopneica e tosse. No exame físico foi observado presença de crepitação em lobos pulmonares e sopro em foco de mitral e tricúspide grau IV\VI. Foi realizada terapia emergencial preconizada até a melhora clínica do animal, e após a ecocardiografia confirmou-se a degeneração valvular mitral e tricúspide, bem como a presença de uma imagem irregular, de ecogenicidade mista, extracardíaca e imóvel na base do átrio esquerdo, medindo 2,9 x 1,44 cm de diâmetro. A terapia clínica instituída estabilizou o quadro clínico por 128 dias, havendo recidiva do edema pulmonar e efusão pleural hemorrágica grave, com os proprietários optando pela eutanásia do animal e a necropsia, confirmando o diagnóstico definitivo do HSA extracardíaco na base do átrio esquerdo.(AU)

Hemangiosarcoma at the base of the left atrium of a dog with mitral and tricuspid valve degeneration ­ case report / Hemangiossarcoma na base do átrio esquerdo de um cão com degeneração da válvula mitral e tricúspide ­ relato de caso

Hemangiosarcoma (HSA) is a malignant neoplasm originating from the vascular endothelium, with high metastatic power and commonly described in the spleen, liver, and right atrium. Thus, the objective of the present study is to report the occurrence of HSA at the base of the left atrium of a male, elderly, Lhasa Apso dog, treated with cyanosis, orthopedic position, cough. In the physical examination, the presence of crackling was observed in pulmonary lobes, murmur in focus of mitral and tricuspid grade IV\VI. The recommended emergency therapy was performed until the clinical improvement of the animal. After echocardiography, mitral and tricuspid valvular degeneration was confirmed, as well as the presence of an irregular, mixed echocardiogram, extra-cardiac, immobile at the base of the left atrium, measuring 2.9 x 1.44 cm in diameter. The clinical therapy established stabilized the clinical picture for 128 days, with recurrence of pulmonary edema and severe hemorrhagic pleural effusion, with the owners opting for euthanasia of the animal and necropsy confirming the definitive diagnosis of extrahepatic SAH at the base of the left atrium.(AU)

O hemangiossarcoma (HSA) é uma neoplasia maligna originada no endotélio vascular, com alto poder metastático e comumente descrito no baço, fígado e átrio direito. Assim, o objetivo deste trabalho é relatar a ocorrência do HSA na base do átrio esquerdo de um cão, macho, idoso, da raça Lhasa Apso, atendido apresentando cianose, posição ortopneica e tosse. No exame físico foi observado presença de crepitação em lobos pulmonares e sopro em foco de mitral e tricúspide grau IV\VI. Foi realizada terapia emergencial preconizada até a melhora clínica do animal, e após a ecocardiografia confirmou-se a degeneração valvular mitral e tricúspide, bem como a presença de uma imagem irregular, de ecogenicidade mista, extracardíaca e imóvel na base do átrio esquerdo, medindo 2,9 x 1,44 cm de diâmetro. A terapia clínica instituída estabilizou o quadro clínico por 128 dias, havendo recidiva do edema pulmonar e efusão pleural hemorrágica grave, com os proprietários optando pela eutanásia do animal e a necropsia, confirmando o diagnóstico definitivo do HSA extracardíaco na base do átrio esquerdo.(AU)

Caracterização histomorfológica do sistema tegumentar auricular de cateto - Pecari tajacu Linnaeus, 1758) / Histomorphological characterization of collared peccary (Pecari tajacu Linnaeus, 1758) ear integumentary system

A criopreservação de tecido somático derivado da pele de catetos consiste numa alternativa para a conservação da biodiversidade por meio da associação com a transferência nuclear. Nesse contexto, a manipulação de tecidos da pele é uma etapa crucial para o sucesso dessa biotécnica. Portanto, o objetivo do presente estudo, foi caracterizar o sistema tegumentar auricular periférico de catetos, visando aprimorar a conservação tecidual. Para tanto, fragmentos auriculares de oito animais foram avaliados quanto às camadas teciduais, aos componentes, à atividade proliferativa e à viabilidade metabólica, usando-se as colorações hematoxilina-eosina e tricrômico de Gomori, quantificação de AgNORs e microscopia eletrônica de transmissão. Assim, tamanhos de 104,2µm e 222,6µm foram observados para epiderme e derme, com uma proporção volumétrica de 36,6% e 58,7%, respectivamente. Além disso, na epiderme, foram evidenciadas as camadas basal (22,5µm), intermediárias (53,5µm) e córnea (28,2µm), com valores médios de 65,3 células epidermais, 43,4 melanócitos e 14,8 halos perinucleares. Já a derme apresentou 127 fibroblastos, com 2,5 AgNORs/nucléolo. Adicionalmente, a atividade metabólica foi de 0,243. Em conclusão, o sistema tegumentar auricular periférico de catetos possui algumas marcantes variações em relação a outros mamíferos, quanto ao número de camadas e espessura da epiderme, quantidade de células epidermais, melanócitos e parâmetros proliferativos.(AU)

The cryopreservation of somatic tissue derived from skin of collared peccaries is an alternative for biodiversity conservation through association with nuclear transfer. In this context, tissue manipulation of skin is a critical step for the success of this biotechnique. Therefore, the aim was to characterize the peripheral ear integumentary system derived from collared peccaries, directing to improve tissue conservation. Thus, ear fragments of eight animals were evaluated for tissue layers, components, proliferative activity and metabolic viability, using hematoxylin-eosin and Gomori Trichrome, AgNORs quantification and transmission electronic microscopy. Hence, sizes of 104.2 µm and 222.6 µm were observed in the epidermis and dermis, with a volumetric ratio of 36.6% and 58.7%, respectively. Moreover, basal layer (22.5 µm), intermediate (53.5 µm) and cornea (28.2 µm), with mean values of 65.3 epidermal cells, 43.4 melanocytes and 14.8 perinuclear halos were evidenced in the epidermal. Already the dermis has 127 fibroblasts with 2.5 AgNORs/nucleolus. Additionally, the metabolic activity was 0.243. In conclusion, the peripheral ear integumentary system derived from collared peccaries possessed some important variations compared to other mammals, as the number of layers and thickness of the epidermis, number of epidermal cells, melanocytes and proliferative parameters.(AU)

Caracterização histomorfológica do sistema tegumentar auricular de cateto - Pecari tajacu Linnaeus, 1758) / Histomorphological characterization of collared peccary (Pecari tajacu Linnaeus, 1758) ear integumentary system

A criopreservação de tecido somático derivado da pele de catetos consiste numa alternativa para a conservação da biodiversidade por meio da associação com a transferência nuclear. Nesse contexto, a manipulação de tecidos da pele é uma etapa crucial para o sucesso dessa biotécnica. Portanto, o objetivo do presente estudo, foi caracterizar o sistema tegumentar auricular periférico de catetos, visando aprimorar a conservação tecidual. Para tanto, fragmentos auriculares de oito animais foram avaliados quanto às camadas teciduais, aos componentes, à atividade proliferativa e à viabilidade metabólica, usando-se as colorações hematoxilina-eosina e tricrômico de Gomori, quantificação de AgNORs e microscopia eletrônica de transmissão. Assim, tamanhos de 104,2µm e 222,6µm foram observados para epiderme e derme, com uma proporção volumétrica de 36,6% e 58,7%, respectivamente. Além disso, na epiderme, foram evidenciadas as camadas basal (22,5µm), intermediárias (53,5µm) e córnea (28,2µm), com valores médios de 65,3 células epidermais, 43,4 melanócitos e 14,8 halos perinucleares. Já a derme apresentou 127 fibroblastos, com 2,5 AgNORs/nucléolo. Adicionalmente, a atividade metabólica foi de 0,243. Em conclusão, o sistema tegumentar auricular periférico de catetos possui algumas marcantes variações em relação a outros mamíferos, quanto ao número de camadas e espessura da epiderme, quantidade de células epidermais, melanócitos e parâmetros proliferativos.(AU)

The cryopreservation of somatic tissue derived from skin of collared peccaries is an alternative for biodiversity conservation through association with nuclear transfer. In this context, tissue manipulation of skin is a critical step for the success of this biotechnique. Therefore, the aim was to characterize the peripheral ear integumentary system derived from collared peccaries, directing to improve tissue conservation. Thus, ear fragments of eight animals were evaluated for tissue layers, components, proliferative activity and metabolic viability, using hematoxylin-eosin and Gomori Trichrome, AgNORs quantification and transmission electronic microscopy. Hence, sizes of 104.2 µm and 222.6 µm were observed in the epidermis and dermis, with a volumetric ratio of 36.6% and 58.7%, respectively. Moreover, basal layer (22.5 µm), intermediate (53.5 µm) and cornea (28.2 µm), with mean values of 65.3 epidermal cells, 43.4 melanocytes and 14.8 perinuclear halos were evidenced in the epidermal. Already the dermis has 127 fibroblasts with 2.5 AgNORs/nucleolus. Additionally, the metabolic activity was 0.243. In conclusion, the peripheral ear integumentary system derived from collared peccaries possessed some important variations compared to other mammals, as the number of layers and thickness of the epidermis, number of epidermal cells, melanocytes and proliferative parameters.(AU)

Avaliação morfológica e elétrica do coração de Bradypus variegatus Schinz, 1825 (Mammalia: Pilosa)

Os bichos-preguiça do gênero Bradypus vêm sofrendo consideravelmente com as pressões antrópicas, o que ressalta a importância de conhecer as peculiaridades desses animais. Sendo assim, realizou-se uma análise detalhada do coração da espécie Bradypus variegatus. Para identificar as características macroscópicas, topográficas, biométricas e vasculares do órgão, efetuaram-se dissecações e mensurações de 15 cadáveres e radiografias digitais do tórax de quatro animais saudáveis. A fim de se observar claramente o perfil coronariano de B. variegatus, três espécimes receberam a injeção arterial de látex com pigmento vermelho, e em um deles, também se fez a injeção venosa, em azul. Para a descrição microscópica, utilizou-se os corações de quatro espécimes. Os órgãos foram fixados em formaldeído tamponado a 10% com tampão fosfato de sódio (PBS) 0,01M e pH de 7,3 e submetidos ao processamento de inclusão em parafina, seguindo-se com os cortes sagitais de 4m de espessura, corados em hematoxilina-eosina. Foram ainda obtidos, perfis eletrocardiográficos de cinco bichos-preguiça com boa saúde. Diante dos resultados coletados, o coração da espécie em questão é cônico, situado obliquamente no mediastino médio, deslocado para a esquerda, apresentando esqueletopias variadas. O órgão é revestido pelo pericárdio e os átrios são internamente, predominantemente lisos, enquanto que nas aurículas são observados músculos pectíneos. Os ventrículos possuem trabéculas cárneas e músculos papilares, dos quais partem cordas tendíneas, que se prendem as válvulas. Foram descritas duas artérias coronárias, uma direita e uma esquerda. De acordo com os achados histopatológicos, nos corações foram visualizadas necroses de diferentes tipos celulares. Endocardiose e processos, inflamatório e degenerativo também foram descritos, com menor prevalência. Com base nos registros eletrocardiográficos, os bichos-preguiça demonstraram ritmo sinusal, com a frequência cardíaca entre 67 e 100bpm. De modo geral, o coração de B. variegatus não apresenta grandes discrepâncias em relação aos demais quadrúpedes.

Sloths of the genus Bradypus have been suffering considerably from anthropic pressure, which highlights the importance of knowing the peculiarities of these animals. Therefore, a detailed analysis of the heart of the species Bradypus variegatus was performed. To identify the macroscopic, topographic, biometric and vascular characteristics of the organ, dissections and measurements of 15 cadavers and digital chest radiographs of four healthy animals were performed. In order to clearly observe the coronary profile of B. variegatus, three specimens received an arterial injection of latex with red pigment, and in one of them, an intravenous injection, in blue, was also performed. For the microscopic description, the hearts of four specimens were used. Organs were fixed in 10% buffered formaldehyde with 0.01M sodium phosphate buffer (PBS) at pH 7.3 and subjected to paraffin embedding processing, followed by 4m thick sagittal sections stained in hematoxylin-eosin. Electrocardiographic profiles of five sloth animals in good health were also obtained. In view of the collected results, the heart of the species in question is conical, located obliquely in the middle mediastinum, displaced to the left, presenting varied skeletonpies. The organ is covered by the pericardium and the atria are internally, predominantly smooth, while pectineal muscles are seen in the atria. The ventricles have fleshy trabeculae and papillary muscles, from which tendinous chords depart, which attach to the valves. Two coronary arteries, one right and one left, were described. According to the histopathological findings, necrosis of different cell types was seen in the hearts. Endocardiosis and inflammatory and degenerative, processes have also been described, with a lower prevalence. Based on electrocardiographic recordings, sloth animals demonstrated sinus rhythm, with heart rate between 67 and 100bpm. In general, the heart of B. variegatus does not show large discrepancies in relation to other quadrupeds.

Determination of left atrial volume in healthy dogs and dogs with myxomatous mitral valve disease / Determinação do volume atrial esquerdo em cães sadios e portadores da degeneração mixomatosa da válvula mitral

The left atrial volume (LAV) can be obtained using the biplane Simpson's method via echocardiography. Although in medicine this parameter has been considered to be a prognostic marker of left atrial enlargement in several cardiac diseases, in dogs with myxomatous mitral valve degeneration (MMVD), a valvulopathy characterized by left atrial (LA) volume overload, atrial enlargement is usually assessed by the LA-to-Aorta ratio (LA:Ao). Therefore, the body surface area (BSA)-indexed LAV was measured in healthy dogs and in dogs with MMVD using the biplane Simpson's method. For this purpose, a total of 107 healthy dogs (control) and 81 dogs with MMVD in ACVIM stages B1, B2 and C were assessed, with LAV being calculated during atrial diastole (d) and systole (s) through the biplane Simpson's method. Two-dimensional apical four-chamber (4C) and two-chamber (2C) images were obtained in every dog through the left parasternal window. The values obtained from healthy dogs were correlated with body weight using Pearson's test. An analysis of variance (ANOVA) and Tukey's test were used to compare healthy and MMVD dogs, as well as to investigate differences according with MMVD stages. A strong positive correlation was documented between either LAVd (r> 0.77) or LAVs (r> 0.73) and body weight in healthy dogs. The BSA-indexed LAV calculated for MMVD dogs was significantly different (p<0.01) from that obtained for the control group. Also, LAV was significantly different (P<0.05) when stages B2 and C, and B1 and C were compared. In conclusion, this study provided a reference for left atrial volume and the applicability of this technique to assess atrial overload in dogs with varying-stage MMVD.(AU)

A mensuração do volume atrial esquerdo (VAE) pode ser obtido pelo método biplanar de Simpson via ecocardiografia. Embora na medicina tal parâmetro venha sendo considerado um marcador prognóstico da sobrecarga atrial esquerda em várias cardiopatias, nos cães com degeneração mixomatosa da válvula mitral (DMVM), valvulopatia caracterizada pela sobrecarga do átrio esquerdo (AE), a avaliação da sobrecarga atrial é realizada rotineiramente apelas pela relação entre o diâmetro do AE e da artéria Aorta (Ao) (AE:Ao). Portanto, procurou-se mensurar os valores do LAV indexados à área de superfície corporal (ASC) em cães sadios e em portadores da DMVM utilizando-se do método biplanar de Simpson. Para tanto, foram avaliados 107 cães sadios (controle) e 81 portadores da DMVM nos estágios B1, B2 e C (ACVIM), sendo o VAE calculado nos momentos da diástole (d) e sístole (s) atrial utilizando o método biplanar de Simpson. Imagens bidimensionais apicais quatro (4C) e duas câmaras (2C) foram obtidas pela janela paraesternal esquerda em todos os cães. Os valores do LAV nos cães sadios foram correlacionados com o peso corporal utilizando o teste de Pearson. Para a comparação dos cães sadios com os portadores da DMVM, bem como para investigar diferenças atribuídas aos diferentes estágios da DMVM, empregou-se análise de variância (ANOVA) e o teste de Tukey. Uma correlação positiva forte foi identificada entre VAEd (r>0,77), VAEs (r>0,73) e o peso corporal dos cães sadios. O LAV indexado pela ASC calculado para os cães portadores de DMVM foi significativamente diferente (p<0,01) daquele obtido no grupo controle. Também foram observadas diferenças significativas (p<0,05) no VAE quando as classes B2 e C, e B1 e C foram comparadas. Em conclusão, este estudo fornece uma referência para o volume atrial esquerdo e a aplicabilidade dessa técnica para avaliação da sobrecarga atrial em cães com DMVM em diferentes estágios.(AU)

Determination of left atrial volume in healthy dogs and dogs with myxomatous mitral valve disease / Determinação do volume atrial esquerdo em cães sadios e portadores da degeneração mixomatosa da válvula mitral

The left atrial volume (LAV) can be obtained using the biplane Simpson's method via echocardiography. Although in medicine this parameter has been considered to be a prognostic marker of left atrial enlargement in several cardiac diseases, in dogs with myxomatous mitral valve degeneration (MMVD), a valvulopathy characterized by left atrial (LA) volume overload, atrial enlargement is usually assessed by the LA-to-Aorta ratio (LA:Ao). Therefore, the body surface area (BSA)-indexed LAV was measured in healthy dogs and in dogs with MMVD using the biplane Simpson's method. For this purpose, a total of 107 healthy dogs (control) and 81 dogs with MMVD in ACVIM stages B1, B2 and C were assessed, with LAV being calculated during atrial diastole (d) and systole (s) through the biplane Simpson's method. Two-dimensional apical four-chamber (4C) and two-chamber (2C) images were obtained in every dog through the left parasternal window. The values obtained from healthy dogs were correlated with body weight using Pearson's test. An analysis of variance (ANOVA) and Tukey's test were used to compare healthy and MMVD dogs, as well as to investigate differences according with MMVD stages. A strong positive correlation was documented between either LAVd (r> 0.77) or LAVs (r> 0.73) and body weight in healthy dogs. The BSA-indexed LAV calculated for MMVD dogs was significantly different (p<0.01) from that obtained for the control group. Also, LAV was significantly different (P<0.05) when stages B2 and C, and B1 and C were compared. In conclusion, this study provided a reference for left atrial volume and the applicability of this technique to assess atrial overload in dogs with varying-stage MMVD.(AU)

A mensuração do volume atrial esquerdo (VAE) pode ser obtido pelo método biplanar de Simpson via ecocardiografia. Embora na medicina tal parâmetro venha sendo considerado um marcador prognóstico da sobrecarga atrial esquerda em várias cardiopatias, nos cães com degeneração mixomatosa da válvula mitral (DMVM), valvulopatia caracterizada pela sobrecarga do átrio esquerdo (AE), a avaliação da sobrecarga atrial é realizada rotineiramente apelas pela relação entre o diâmetro do AE e da artéria Aorta (Ao) (AE:Ao). Portanto, procurou-se mensurar os valores do LAV indexados à área de superfície corporal (ASC) em cães sadios e em portadores da DMVM utilizando-se do método biplanar de Simpson. Para tanto, foram avaliados 107 cães sadios (controle) e 81 portadores da DMVM nos estágios B1, B2 e C (ACVIM), sendo o VAE calculado nos momentos da diástole (d) e sístole (s) atrial utilizando o método biplanar de Simpson. Imagens bidimensionais apicais quatro (4C) e duas câmaras (2C) foram obtidas pela janela paraesternal esquerda em todos os cães. Os valores do LAV nos cães sadios foram correlacionados com o peso corporal utilizando o teste de Pearson. Para a comparação dos cães sadios com os portadores da DMVM, bem como para investigar diferenças atribuídas aos diferentes estágios da DMVM, empregou-se análise de variância (ANOVA) e o teste de Tukey. Uma correlação positiva forte foi identificada entre VAEd (r>0,77), VAEs (r>0,73) e o peso corporal dos cães sadios. O LAV indexado pela ASC calculado para os cães portadores de DMVM foi significativamente diferente (p<0,01) daquele obtido no grupo controle. Também foram observadas diferenças significativas (p<0,05) no VAE quando as classes B2 e C, e B1 e C foram comparadas. Em conclusão, este estudo fornece uma referência para o volume atrial esquerdo e a aplicabilidade dessa técnica para avaliação da sobrecarga atrial em cães com DMVM em diferentes estágios.(AU)