ABSTRACT
BACKGROUND: Veterinary cardiology, especially electrocardiography, has shown major advancements for all animal species. Consequently, the number of ovine species used as experimental animals has increased to date. Few studies have been published on ovine systematic electrocardiography, particularly with respect to lamb physiology and neonatology. This study aimed to standardize the values of normal waves, complexes, and intervals of the electrocardiogram (ECG) in clinically Bergamasca healthy neonatal lambs, used as experimental animals. Serial computerized electrocardiography was performed in 10 male and 12 female neonates on the 1st, 7th, 14th, 21st, 28th, and 35th days of age. The following parameters were analyzed: heart rate and rhythm, duration and amplitude of waves, duration of intervals, and heart electrical axis. RESULTS: During the first 35 days of life, (1) the sinusal heart rhythm was predominant, (2) there was a progressive decrease in the heart rate and R and T wave amplitude, and (3) a progressive increase in the PR, QT, and RR intervals. Finally, we confirmed that various components of neonatal evolution were more discernible in the augmented unipolar leads (aVF), which we recommend should be preferentially used in future studies. No significant statistical alterations were observed between males and females in relation to the analyzed parameters. CONCLUSIONS: The information assimilated in this study is anticipated to enhance the diagnosis of multiple congenital heart defects in Bergamasca lambs and could be implemented in studies that use ovine species as experimental models.
Subject(s)
Animals, Newborn/physiology , Consciousness/physiology , Heart/physiology , Sheep/physiology , Animals , Coronary Sinus/physiology , Disease Progression , Electrocardiography/methods , Female , Heart Rate/physiology , MaleABSTRACT
O objetivo deste estudo foi analisar e comparar os registros eletrocardiográficos de 50 equinos American Miniature Horse, clinicamente saudáveis, obtidos pelos métodos convencional e computadorizado, para a padronização do método informatizado. As medidas de duração e amplitude das ondas e intervalos e frequência cardíaca foram analisadas nas derivações do plano frontal e na derivação base-ápice. Diferenças quanto à duração da onda P, foram encontradas nas derivações I e aVL, e do complexo QRS, em todas as derivações do plano frontal. Quanto à derivação base-ápice, houve diferença na duração do intervalo QT e da onda T, assim como na amplitude da onda S. Concluiu-se, portanto, que ocorre superestimação da duração do complexo QRS no método computadorizado e que, devido às diferenças inerentes de cada método, torna-se importante a utilização de valores de referência para o método computadorizado também na espécie equina.
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.
