A new ECG recording technique has been developed which can quickly detect a difficult-to-diagnose heart condition in horses.
Paroxysmal atrial fibrillation (PAF), which can be fatal in horses, is also a major cause of stroke in humans.
The new rapid diagnostic method offers hope of easier stroke prevention in humans.
In a study published in the journal Nature Scientific Reports, researchers from the University of Surrey in England describe how they developed the rapid and inexpensive technique to identify the condition.
PAF causes rapid, erratic heart beats in horses.
However, because of the intermittent nature of the condition, it is often difficult to diagnose and can affect a horse’s racing performance and even cause death in some cases.
In humans, this arrhythmia can be dangerous as it can cause disruption of blood flow in the upper two chambers of the heart, which could lead to blood clots in the organ. Such clots could block blood vessels elsewhere in the body, including the brain, resulting in cognitive decline and ischemic strokes.
During the study, ECG recordings were obtained during routine clinical work from healthy horses and those with a diagnosis of PAF.
ECG traces with no other electrical disturbances were converted to a string of computational numbers using a range of detection algorithms.
It was found that ECG results recorded at rest (with a low heart rate of 25–60 beats per minute) and processed by the novel detection method, were found to be significantly different between horses with and without PAF.
This allowed the identification of horses with PAF from sinus-rhythm ECGs with high accuracy.
Timely detection of PAF is crucial for effective treatment of the condition. Electrical stimulation or anti-arrhythmic drugs could restore the normal heart rhythm and anti-coagulation drugs might prevent the formation of blood clots preventing strokes or greatly reducing their consequences.
“I am very happy to see that in horses we obtained such excellent results and came up with a tool which could be easily used even by a non-professional,” said Dr Vadim Alexeenko, a research fellow at the School of Veterinary Medicine at the university and lead author of the study.
“It was also very exciting to devise the new approach of ECG parsing, which is absolutely essential for high sensitivity and specificity of our method.”
The head of this research team, Dr Kamalan Jeevaratnam, said the fascinating aspect of the study was that they were looking at an arrhythmia typically provoked by a high heart rate, but were diagnosing it looking at low heart rate recordings.
“There is no need to exercise the horse and the analysis could be done in minutes, using low power computers. As a clinician, I think such analysis will greatly facilitate detection of this arrhythmia and it will promote the use of ECG by my colleagues.”
In line with the university’s One Health agenda, Dr Jeevaratnam is now talking with other groups in Britain and the United States to move this research into human studies, whilst in parallel exploring the potential of partnering with device companies in the equine industry.
The study was funded by the PetPlan Charitable Trust.
Alexeenko, V., Fraser, J.A., Bowen, M. et al. The complexity of clinically-normal sinus-rhythm ECGs is decreased in equine athletes with a diagnosis of paroxysmal atrial fibrillation. Sci Rep 10, 6822 (2020). https://doi.org/10.1038/s41598-020-63343-7