Electrocardiography and heart score of horses competing in an endurance ride.

The research studied the relationship between the electrocardiogram (ECG) readings of horses and their performance in endurance riding. The prevailing outcome was that ECG serves as a valuable tool in determining the apptitude of the horses but cannot be used solely for this purpose.

Research Methodology

• The study involved 15 Engish-Arab-Hannoverian (Eah) horses aged between 7 and 12.
• The endurance competition was carried out in spring near Madrid, with temperatures ranging from 18 to 20°C and an atmospheric pressure of 706 mm Hg.
• All the horses were required to perform identical tasks of one turn about a 3 km circuit followed by a 10-minute resting period for a fitness check. This process was repeated for 6 hours and the team completing the most turns was declared the winner.
• Prior to the exercise, all horses’ health and fitness were checked and their ECG recorded using six-leads (I, II, III, aVR, aVL, aVF), which was carried out using a single channel, battery-operated cardiography machine.
• After each round of exercise, another ECG was recorded for comparison with the pre-exercise ECG.
• The ECG’s were examined focusing on various measures such as P wave, QRS complex potential, ST space, T wave potential, etc.

Key Findings

• The study established that there are variations in electrocardiographic waves of the same horse before and after work and noted that there were variations between the performance in the race and the ECG readings.
• Based on the results of the heart scores calculated using average QRS complex duration, it was observed that horses with heart score greater than 116ms are usually regarded as suitable for the sport. However, only one horse with such a score was found in this study, which was part of the winning team.
• Consequently, the study found that horses with heart scores less than 103ms have potential poor performance. In this study, nine of the fifteen horses tested had heart scores less than 103ms. Two of these horses which had heart scores less than 100ms were part of the team that finished last.

Conclusion

• While there were clear connections between the electrocardiograms of horses and their performance capacity, it was concluded that an electrocardiogram alone is insufficient in determining the athletic aptitude of a horse.