Parámetros electrocardiográficos en caballos de raza Criollo Colombiano, pacientes de un establecimiento veterinario de Antioquia, Colombia

Abstract

Las alteraciones cardiacas en los equinos no se manifiestan de una manera habitual como en otros animales; sin embargo, hay afecciones que requieren ser diagnosticadas correctamente para evaluar el desempeño atlético. Son varios los estudios publicados respecto a la utilización de métodos diagnósticos complementarios en cardiología equina, como el electrocardiograma (ECG). A pesar de ello aún no se tienen datos de referencia para el caso del Caballo Criollo Colombiano (CCC). El objetivo de este estudio fue describir los trazados electrocardiográficos de 57 CCC pacientes de la Clínica Veterinaria Lasallista, con alta previa y sin alteraciones clínicas evidentes. Los ECG fueron hechos en sistema base ápex y los animales fueron divididos en grupos de edad. Para el análisis de los datos se hizo estadística descriptiva, análisis de varianza de una vía y coeficientes de correlación. De cada grupo se obtuvieron rangos de amplitud y duración de las diferentes ondas, intervalos y segmentos. Solo se evidenció diferencia estadísticamente significativa de la duración de la onda P e intervalo PR entre grupos de edad. Existieron correlaciones de algunos de los parámetros del ECG con el peso, la edad y la frecuencia cardiaca. Con este trabajo se hace un aporte importante para aquellas ocasiones en que sea necesario recurrir al electrocardiograma para validar la información obtenida en el examen clínico o cuando se sospeche de una cardiopatía en CCC, principalmente, en el caso de arritmias.

Morphometric analysis of the His bundle (atrioventricular fascicle) in humans and other animal species, associated with electrophysiological variables. Histological and immunohistochemical study

“…Horses belong to group I suggested by us in HB and although pigs also belong to this group due to the similar histological characteristics found, we observed a short PR segment at rest (0.08 seconds) on the electrocardiogram (Fernandez et al 2003; Wang et al 2015; Zhang et al 2016), which would indicate a faster transmission of the electrical impulse in the atrioventricular zone similar to that described in the species belonging to group II as we will indicate later. What does coincide with our histological ndings in HB and AV nodes in horses and pigs at rest is that in these species the heart rate (38-56 beats in horses and 55-86 beats in pigs) (Fernandez et al 2003;Guerrero et al 2009;Mira et al 2016;Zhang et al 2016) is slower, possibly due to the amount of collagen bers present in these structures of the conduction system. This indicates that the transmission of the electrical impulse through HB in these species could be slower, which would justify the large number of nerve bers that help make the impulse´s passage more effective.…”

“…AV node is responsible for receiving electrical impulses from the sinus node and one of its main functions is to produce a delay in the transmission of that electrical impulse to the ventricles for its protection. In horse literature at rest, we nd a long PR segment (0.14 seconds) on the electrocardiogram (Corredor-Matus et al 2005;Mira et al 2016;Mitchell 2019;Van Steenkiste et al 2020) that coincides with a large number of collagen bers and large cells in HB reported in our study, which would explain a slower transmission of the electrical impulse when atrial to ventricular activation occurs. Horses belong to group I suggested by us in HB and although pigs also belong to this group due to the similar histological characteristics found, we observed a short PR segment at rest (0.08 seconds) on the electrocardiogram (Fernandez et al 2003;Wang et al 2015;Zhang et al 2016), which would indicate a faster transmission of the electrical impulse in the atrioventricular zone similar to that described in the species belonging to group II as we will indicate later.…”

“…Regarding ventricular activation in group I species, we found in previous reports a wide QRS complex in horses (0.19 seconds) and narrow in pigs (0.05 seconds) at rest (Fernandez et al 2003;Corredor-Matus et al 2005;Wang et al 2015;Mira et al 2016;Zhang et al 2016;Mitchell 2019;Van Steenkiste et al 2020), which could be correlated with the characteristics of Purkinje bers (PF) in both species, being PC very large and surrounded by thin sheaths of collagen bers (Canale et al 1986;Ono et al 2009), despite the difference in duration of the QRS complex in horses and pigs (Fernandez et al 2003;Corredor-Matus et al 2005;Wang et al 2015;Mira et al 2016;Zhang et al 2016;Mitchell 2019;Van Steenkiste et al 2020). Thanks to these characteristics, these bers have conduction properties and facilitate rapid propagation of the electrical impulse, like in humans (Oosthoek et al 1993;Ono et al 2009;De Almeida et al 2015).…”