Electrocardiographic methods in equines American Miniature Horse/ Metodos eletrocardiograficos em equinos American Miniature Horse

The aim of this study was to analyze and compare electrocardiographic records of 50 horses American Miniature Horse, clinically healthy, obtained by conventional methods and computerized, to the standardization of the computerized method. The measures of duration and amplitude of waves and intervals and heart rate were analyzed in the leads of the frontal plane and base-apical lead. Differences about the duration of the P wave were found in I and aVL derivations, and QRS complex, in all derivations of the frontal plane. As for basis-apical derivation, there was no difference in the duration of the QT interval and the T wave and the amplitude of the S wave, therefore concluding that overestimation occurs in the duration of the QRS complex in computerized method and that due to inherent differences of each method, it becomes important the use of reference values for the computerized method also in the equine species. Key words: horse, computerized electrocardiogram, conventional electrocardiogram, ponies. O objetivo deste estudo foi analisar e comparar os registros eletrocardiograficos de 50 equinos American Miniature Horse, clinicamente saudaveis, obtidos pelos metodos convencional e computadorizado, para a padronizacao do metodo informatizado. As medidas de duracao e amplitude das ondas e intervalos e frequencia cardiaca foram analisadas nas derivacoes do plano frontal e na derivacao base-apice. Diferencas quanto a duracao da onda P, foram encontradas nas derivacoes I e aVL, e do complexo QRS, em todas as derivacoes do plano frontal. Quanto a derivacao base-apice, houve diferenca na duracao do intervalo QT e da onda T, assim como na amplitude da onda S. Concluiu-se, portanto, que ocorre superestimacao da duracao do complexo QRS no metodo computadorizado e que, devido as diferencas inerentes de cada metodo, torna-se importante a utilizacao de valores de referencia para o metodo computadorizado tambem na especie equina. Palavras-chave: cavalo, eletrocardiograma computadorizado, eletrocardiograma convencional, poneis.