ECG test could highlight equine exercise arrhythmias
Earlier identification of horses at risk of cardiac arrhythmia could improve the welfare of racehorses.
A routine electrocardiogram (ECG) could reveal horses at risk of cardiac arrhythmias during high-intensity exercise.
In a new study, led by the University of Surrey, researchers suggest that ECGs could prevent cardiac events in otherwise healthy horses, even when there are no obvious signs of arrhythmia.
Researchers recorded ambulatory ECGs from 110 US-based Thoroughbred and Standardbred racehorses as they underwent routine training. Using 60-second ECG segments from each horse, they tested six different AI algorithms.
The artificial intelligence system, developed at the University of Surrey, is trained to measure the ‘disorderliness’ of the heart’s electrical signal. It is able to recognise the horses most likely to develop premature beats at peak exercise, using short ECG readings taken at rest or during exercise.
The best-performing algorithm achieved an area under the curve of 0.86 in distinguishing horses with exercising arrhythmias.
Most importantly, the test was also highly effective at ruling out horses that were not at risk of exercising arrhythmias. Horses which do screen positive can then be referred for a full exercising ECG, which would confirm the type and severity of any arrhythmia.
The current method for diagnosing cardiac arrhythmias would see vets monitor ECGs during high-intensity exercise. Earlier identification of horses at higher risk of cardiac arrhythmia is expected to lead to more informed monitoring and management, particularly improving the welfare of racehorses.
It builds upon research from the Jeevaratnam group, which previously demonstrated how complexity-based ECG analysis could detect paroxysmal atrial fibrillation. Since the methods work at different heart rate ranges, vets could screen for both conditions with a single diagnostic session.
Prof Kamalan Jeevaratnam, head of the School of Veterinary Medicine at the University of Surrey, said: “What this work shows is that we can pick up warning signs for more impactful rhythm disturbances from a simple, short heart recording taken before the horse ever reaches peak intensity.
“Instead of waiting for an arrhythmia to appear, we can flag at-risk horses during a routine warm-up and support closer monitoring of these horses during exercise.”
Image © Mick Atkins/Shutterstock.com
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