Cinthia Beatriz da Silva Dumont

Parâmetros eletrocardiográficos de equinos Puro Sangue Árabe submetidos a exercício prolongado de enduro

Electrocardiographic parameters of 20 Thoroughbred Arabian horses were established at rest and after prolonged endurance exercise. The mean heart rate was 35.85bpm at rest with predominant sinus rhythm, and 53.78bpm with sinus tachycardia after exercise. As physiological variation, wandering pacemaker was observed, and as non physiological, premature ventricular complex was noted. At post-exercise there was an increase of the amplitude of waves P, R, S and T, with P wave tending to become single in 35% of the animals and bifid positive in 65%, and with monophase positive T wave. There was a reduction in the duration of the waves, intervals and segments, and elongation of QTc, but the QRS complex hardly changed. The electrical axis in the frontal plane showed deviations to the right and to the left at rest, suggesting chamber enlargement and hypertrophy secondary to training, while after the exercise it showed extreme deviation to the right, indicating electrolyte imbalances. The average heart score was 128.45ms, which features the animals as athletes, being reduced to 118.60ms after exercise.

Avaliação eletrocardiográfica de equinos após exercício de polo (baixo handicap)

Electrocardiography can be used to quantify the training and athletic performance as well as evaluating the cardiac function under the effect of exercise identifying the influence of cardiac anomalies, and deleterious effects of stress ahead of heart function. Considering the complexity of the physical efforts inherent in polo ponies in competitions, together with the lack of reports in the literature, on the demand resulting for heart. The aim of this study was to identify and evaluate the cardiac effects of electrocardiographic exercise in polo horses in order to support data for understanding the physiological cardiac demand of this sport. We evaluated 27 equine practitioner polo at rest and between five and ten minutes after exercise. The results showed that the observed changes in the duration and P wave amplitude and duration of PR and QT interval were considered in physiological response to increased heart rate. The diphasic P wave found at rest and when atrial hypertrophy represented bifida represented different points of activation of the sinoatrial node. As expected, the QRS complex has not undergone major changes. The ST-segment elevation and T wave changes observed after exercise could pose adverse effects to the myocardium, but studies examining multiple factors are needed to confirm this association and define your actual question. The increase in QTc suggested fatigue mild myocardial represented high heart demand for this type of exercise. The heart score showed that these animals were within the pattern of cardiac adaptation to a horse athlete. The rapid recovery of HR showed good conditioning of these animals. The pacemaker migration was observed in most animals proven to be a normal finding horse athlete. We observed a low incidence of changes in cardiac rhythm.

Parâmetros eletrocardiográficos de equinos desclassificados por exaustão em competições de enduro

By using electrocardiographic examination, 14 Purebred Arabian horses, 12 males and two females, disqualified due to exhaustion in endurance races from 60 and 160km were evaluated. Predominance of sinus tachycardia, followed by sinus arrhythmia and atrial premature complex, with the heart rate ranging from 48 to 78bpm, and 93 to 111bpm, respectively, were observed. There was increase in the amplitude of waves P, R, S, and T, and decrease in their durations, as well as reduction in the intervals and segments; nevertheless, the QRS complex was not almost altered. The QTc lengthening pointed to a moderate myocardial fatigue in response to exercise, and the elevation of ST was indicative of hypovolemia. The electrical axis in frontal plane presented deviation to the right, chamber increase, and hypertrophy secondary to training

Osmolaridade, ânion gap, potencial hidrogeniônico e íons plasmáticos mensuráveis de equinos Puro Sangue Árabe

We evaluated the behavior of osmolality, anion gap, pH and measurable plasma ions of 14 Purebred Arabian horses, 9 males and 5 females, finalists in an endurance race of 90 km. In order to achieve this, we collected venous blood samples twice, at rest and after prolonged exercise, in order to measure the interest variables. The results allowed to observe that from the rest an increase with significant difference in the values of Hct, PPT and AG, suggesting loss of fluids and slight dehydration. The pH and the H+ ion almost had no changes, indicating absence of metabolic disorders. Reductions, with significant difference, were verified for the ions Cl-, HCO3-, K+, Ca++, as well as BE. These data suggest that the type of exercise to which the animals were submitted was consistent with the athletic ability and that supplementation during the competition contributed to minimize such losses.

Expressão do Mg+2, CK, AST e LDH em equinos finalistas de provas de enduro

In recent years, due to rising competitive demands, the equine athlete is being increasingly required. Thus, the demands for high performance have fostered interest in the study of pathophysiology of various horse diseases. The relationship between magnesium and exercise has received significant attention because this ion is closely related with the skeletal muscle tissue. Moreover, among the main strategies for the detection and monitoring of clinical muscle damage, features the evaluation of the activity of the enzymes creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). The search for the establishment of parameters that relate to each other is a determining factor in understanding the physiological changes found on athletic horses in effort. Thus, this study aimed to determine how the blood concentrations of magnesium ion and the enzymatic activities of the enzymes CK, LDH and AST behave in Arabian finalist horses in endurance races of 90km and to relate possible changes to the type of physical effort played by animals. It was evaluated the enzymatic activities of the enzymes CK, LDH, AST e the concentration of the ion magnesium in exercise in relation to the rest state of 14 clinically healthy Arabian horses, 9 males and 5 females, with ages ranging from 6 to 12 years, undergoing endurance training and participants in 90 km distance rides. All variables evaluated had an increase with statistical differences in relation to rest. The physical endurance exercise determined the occurrence of changes in enzyme activities of CK (p≤0.001), LDH (p=0.0001), AST (p=0.0007) and in the concentration of magnesium ion (p=0.0004), in exercise in relation to rest (p≤0.05). Fact that determined changes in permeability of striated skeletal muscle cells, suggesting the establishment of an acute inflammatory process. Mainly due to the expression of enzymatic activity of CK (p≤0.001), for its specificity in relation to the damage to skeletal striated muscles, along with the magnesium ion (p=0.0004) that actively acts in various cellular reactions. There were changes in total plasma protein concentrations (p=0.0009) and hematocrit (p=0.0001), between the evaluated moments. Therefore, these results serve as a reference of support equine finalists in an endurance race of 90 km, aiding in the prevention of the occurrence muscle damage and severe inflammatory processes.

Avaliação ecocardiográfica de equinos após exercício de polo

Considering the complexity of the physical effort inherent in polo horses in competitions and the lack of reports about the cardiovascular effects resulting from a Chukker, yet the dynamics of the associated weight, the aim of this study was to evaluate by echocardiography with 27 horses polo athletes who underwent training starting at rest and after exercise. The results showed that this method has changed several echocardiographic indexes within five to ten minutes before the end of a Chukker. It was they, as structural index, thickness reduction interventricular septum and left ventricular free wall and increased left ventricular diameter, and functional as an increase in cardiac output and heart rate, while stroke volume, fractional shortening and ejection fraction reduced. The weight loss was not significant, so was not associated with echocardiographic changes. These results suggest that cardiac demand was high, indicating the importance of the physical and cardiovascular training specific to this modality.

Comparação de dois métodos de colheita de medula óssea de equinos e de dois meios de diluição para o isolamento de células mononucleares

The aim of this study was to evaluate mononuclear cells fraction (MCF) concentration and viability from different techniques of bone marrow (BM) aspiration and processing in horses. Five adult horses, healthy and of unknown breed were evaluated. BM was obtained from sternum bone, according two protocols: in aspiration A, 10mL of heparin solution was used inside the syringe and BM was aspirated; in aspiration B, 10mL of heparin solution was injected into the BM, and aspiration was done after 20 seconds. All the animals were submitted by both protocols realized in sequence, without a gap between the procedures. After MCF isolation, of BM samples obtained from A and B aspiration, each sample was divided into two tubes; one contained DMEM solution and the other with PBS solution. Therefore, interchanging the aspiration protocol and the dilution solution, four sample tubes were obtained for each horse. The tubes were centrifuged and the pellet was homogenized with the respectively solution to obtain the final volume of 100μL. Cellular concentration and viability were determined to obtain the FCM medium concentration. For both solutions, the aspiration B had higher numeric values comparing with aspiration A; however, it was not significant (p>0.05). This tendency is attribute for the less BM coagulation observed in the aspiration B, suggesting greater improvement of MCF. No difference (p>0.05) was found between DMEM and PBS solution, indicating that both do not alter the cell viability. The protocols used for BM aspiration and MCF isolation were efficient for application in equine cellular therapy.

Hemogasometria venosa de equinos finalistas de provas de enduro de 90 km

Front of exercise, the organic systems may suffer water-electrolyte and acid-base imbalances, particularly in the case of blood gases, demonstrating variations from different causes, whether respiratory and/or metabolic. Understanding the physiological adaptations to exercise is essential in the search for the optimum performance. In this way, this study measured the venous blood gases (pO2, pCO2), as well as the oxygen saturation (SatO2) in healthy equines, Arabian horses finalists in 90km endurance races. A total of fourteen Arabian horses were evaluated, nine males and five females, between six and 12 years old, finalists in 90km endurance races. There was a significant reduction in pO2, pCO2 and SatO2 after the exercise, however, the values remained within the normality range, and did not change the athletic performance of the animals, indicating a temporary alteration, assuming thus a character of physiological response to the exercise performed. The equines, finalists in 90 Km endurance races, demonstrated efficient ventilatory process, without any alterations in the athletic performance, being adapted to the type of exercise imposed.

Physiological Demands and Changes Resulting from Effort in Low Handicap Polo Horses

In order to understand the physiological demands and possible changes resulting from effort in horses and determine the type and intensity of exercise performed in equestrian polo of low handicap, we analyzed the negative logarithm of the activity of hydrogen ions (pH), carbon dioxide partial pressure (pCO2), oxygen partial pressure (pO2), the concentration of plasma bicarbonate ions (HCO3-) and serum concentrations of Na+, Cl- and K+ of seven healthy horses after a polo match of low handicap. Variables pCO2, pO2 and HCO3- were the only parameters that were significantly different before and after the match, and there were no significant hydroelectrolytic changes. It was possible to classify the low handicap polo as an exercise of short duration and varying intensity, considering the lack of change in the hydroelectrolytic balance. The exercise to which the animals were subjected is compatible with their athletic fitness.