摘要：A study was made of the electrocardiograms of 16 Andalusian horses, with two controls, before and after three months’ training, in order to assess the electrocardiographic changes taking place as a result of a defined training period. Five precordial leads were used, placing the electrodes in different locations around the thoracic cavily. The P wave and the QRS complex have shown some morphological modifications induced by training. Moreover, daily exercise gave rise to substantial variations in quantitative electrocardiographic parameters. There was a decrease in the duration of P, R and T waves, and in the voltage of P and R waves. A greater duration was recorded for the segments PQ, ST and TP, and for the intervals RR, PQ and TQ. The duration of intervals QRS and QT, however, was shorter. Finally, a greater number of changes related to training were observed by using the precordial leads than the semiorthogonal system.
