Electrocardiogram
The electrocardiogram parameters were presented in Table 1.
Heart rate and P wave amplitude were significantly increased after exercise when compared to before exercise. Duration of P wave, PQ interval, QT interval and RR interval were significantly shorter after exercise when compared to before exercise. There was no significant change in QRS complex duration, T wave amplitude and duration in before and after exercise.
In the present study, before exercise 16 horses had bifid P-wave and 2 horses had a single P-wave. After exercise, 7 horses had bifid p-wave and 11 horses had single P-wave. (Fig. 1)
In the present study, before exercise 12 horses had negative T-wave and 6 had positive T-wave. After exercise 13 horses had positive T waves and 5 had negative T waves. (Fig. 2) ST coving was noticed in two horses after exercise.
No arrhythmias were noted before exercise but after exercise two horses had sinus arrhythmia. One horse had sinus tachycardia (HR= 105 bpm) (Fig. 4) and another one had second degree AV block Mobitz type I. (Fig. 3)