Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings.
Authors: Flethøj Mette, Kanters Jørgen K, Pedersen Philip J, Haugaard Maria M, Carstensen Helena, Olsen Lisbeth H, Buhl Rikke
Journal: BMC veterinary research
Summary
# Editorial Summary Beat-to-beat variation in equine heart rhythm presents a genuine diagnostic challenge because horses naturally exhibit greater cardiac irregularity than other species, yet standardised thresholds for distinguishing normal variation from pathological arrhythmias remain poorly defined in equine practice. Flethøj and colleagues addressed this gap by developing and validating a two-step timing algorithm for semi-automatic ECG analysis in 21 healthy adult endurance horses, establishing objective threshold criteria for acceptable RR interval deviation that could improve the consistency and reliability of arrhythmia detection. Their novel algorithmic approach successfully quantified baseline arrhythmia frequency in this cohort, providing reference data that clinicians can use to differentiate clinically insignificant beat-to-beat irregularities from genuine premature beats or conduction abnormalities requiring investigation. These standardised threshold levels offer farriers, veterinarians, and performance coaches a more rigorous framework for interpreting ECG findings, reducing the likelihood of over-diagnosis of benign rhythm variations that are particularly common in fit endurance horses. Adopting such validated criteria strengthens clinical decision-making around cardiac fitness assessment and helps avoid unnecessary restrictions on athletic horses presenting with normal sinus arrhythmia or other benign rhythm features.
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Practical Takeaways
- •ECG interpretation in horses now has evidence-based threshold criteria for distinguishing normal rhythm variation from clinically significant arrhythmias, improving diagnostic accuracy
- •The two-step algorithm provides a standardized, reproducible method for analysing equine ECG recordings, reducing subjective interpretation errors
- •Understanding normal cardiac beat-to-beat variation in horses helps clinicians better identify premature beats and other arrhythmias that warrant intervention
Key Findings
- •Established standardized threshold levels for maximum acceptable RR interval deviation in equine ECG analysis to distinguish normal variation from pathological arrhythmias
- •Developed and validated a novel two-step timing algorithm for semi-automatic ECG analysis in healthy adult endurance horses
- •Identified normal beat-to-beat variation parameters in equine cardiac rhythm previously lacking standardized criteria