Eletrocardiografia e ecodopplercardiografia: análise de viabilidade e padronização da técnica e dos parâmetros referenciais em caprinos.

Abstract

Goats, like any other domestic animal, may present either primary or secondary cardiovascular disorders (CVD). However, the lack of knowledge about the indicators of a compromised system in this species causes an overlapping of clinical signs of cardiovascular changes and limits the therapies and more specific interventions. Therefore, although seldom applied in the clinic for small ruminants, complementary diagnostic techniques such as electrocardiography and echocardiography are essential as diagnostic methods to elucidate heart diseases and even those that lead to cardiovascular repercussions on its course. However, these diagnostic techniques require experimental studies in healthy animals to establish reference parameters, to reiterate their importance for the species, so it can be included as an experimental model in the cardiovascular scientific segment. Thus, the objective of this study was to provide consistent data that will contribute to the development of Cardiology of Small Ruminants with standardization of diagnostic tools such as electrocardiography and echocardiography in goats, as well as to determine reference values that may contribute to heart disease diagnosis and cardiovascular studies that adopt goats as an experimental model. Chapter I consists of an analysis of the factors that influence the mean electrical axis and the lead system in goats. It was concluded that only body position influences the direction of the mean electrical axis of the hexaxial lead system in adult goats. Whereas the "Quadrupedal" stance affected the least the mean vector of ventricular depolarization and could be adopted to standardize the other electrocardiographic parameters. Chapter II describes that the electrocardiographic recording system of the frontal plane leads (Hexaxial System) causes great morphological variability of parameters, especially the QRS complex and TMV wave, thus compromising their standardization due to the inconsistency of the data, and not allowing its adoption as a reference. Finally, Chapter III states that the standardization of Doppler echocardiographic parameters, in goats, should always consider breed, age and body weight, as observed in other species. Repeatability and reproducibility studies, and research to adopt comparison reference indices based on individual variables, especially the M-mode cardiac parameters, are essential to establish reliable normal standards and therefore to evaluate possible heart disease in goats.