2. Universidad Cardenal Herrera-CEU

Equine ventricular repolarisation wave can be influenced by many physiological and pathological factors. T wave abnormalities have been related to a shorter time for ventricular filling, reduced stroke volume, cardiac output and exercise performance in racehorses. The present research performed electrocardiographic recordings in 14 four-year-old male Andalusian horses, when they were untrained and after three months of an aerobic training programme. Leads I, aVF, V10, V1R, V3R, V1L and V3L were used. It was aimed to assess the incidence of abnormal T waves in this breed, according to the criteria of abnormalities established for other equine breeds, to evaluate if the changes induced by training in the T wave are the same that those reported in the athletic heart syndrome in canine and human athletes and, to analyse if the abnormal T waves could have been related to changes in the plasma concentrations of Na, K, and Cl, since these electrolytes are involved in the cardiac electrical processes. It was found out that the incidence of abnormal T waves was quite high in the Andalusian breed, especially in the precordial leads. Moreover, the incidence of abnormal T waves increased in precordial leads and decreased in lead I and aVF after training. The abnormal T waves after training were shorter and had the same voltage, changes which were different to those presented for the athlete’ heart syndrome. The horses with abnormal T waves had higher plasma K concentrations, both before and after training. Plasma Na and Cl concentration at rest decreased after training. Plasma Na concentrations were positively related to T wave duration and negatively to T wave voltage.

El objetivo de este trabajo ha sido describir un sistema de pun-tuación objetivo, a partir de índices de funcionalidad cardiovas-cular y metabólica, que permita la discriminación entre caba-llos según su potencial atlético. Se han estudiado 45 caballosadultos, Pura Raza Española (PRE), machos. Tras un calenta-miento al trote (4 m/s), los animales realizaron un test de ejer-cicio, a velocidades de 5, 6,7y8m/s, cubriendo 1.000 m encada carga de esfuerzo. Se monitoreó la frecuencia cardiaca(FC) y se extrajeron muestras de sangre venosa en reposo,tras el calentamiento, después de cada fase del test y a los 2,4, 6, 8, 10, 15 y 30 minutos de una recuperación activa. Ensangre entera, se determinó la concentración de hemoglobina(HB) y el valor hematócrito (HTO). En plasma, se midieron losniveles de lactato (LA). Los índices de funcionalidad oxidativoshan sido: HBo’ y HTOo’ (HB y HTO a 8 m/s), V150 y VLA2 (ve-locidad a 150 lpm y 2 mmol/L de LA respectivamente), FCLA2(FC a 2 mmol/L de LA) y LA150 (LA a 150 lpm). Como índicesglicolíticos-mixtos, se han considerado: FCmáx (FC máxima),FCo’ (FC a 8 m/s), LAmáx (LA máximo), V200 y VLA4 (veloci-dades a 200 lpm y 4 mmol/L de LA), FCLA4 (FC a 4 mmol/Lde LA) y LA200 (LA a 200 lpm). Los índices que mejor han dis-criminado a los caballos PRE según su nivel de forma físicahan sido VLA2, LA150 y HTOo’ (oxidativos) y FCo’, VLA4 yV200 (glicolíticos-mixtos). VLA2, VLA4 y V200 estuvieron co-rrelacionados positivamente con el potencial físico y FCo’,HTOo’ y LA150, de modo negativo.