Paroxysmal Atrial Fibrillation in Horses: Pathophysiology, Diagnostics and Clinical Aspects.
Authors: Kjeldsen Sofie Troest, Nissen Sarah Dalgas, Buhl Rikke, Hopster-Iversen Charlotte
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary: Paroxysmal Atrial Fibrillation in Horses Paroxysmal atrial fibrillation (pAF) represents a particularly challenging diagnosis in equine practice because episodes occur intermittently, potentially going undetected during standard clinical examination despite causing significant performance loss. This literature review synthesises current understanding of pAF pathophysiology, drawing parallels with human medicine to explain how the condition arises and progresses, and evaluates diagnostic approaches including auscultation, resting electrocardiography and extended cardiac monitoring. The key clinical concern is that untreated pAF initiates electrical and structural remodelling of the atrial myocardium, progressively creating conditions that sustain the arrhythmia and may eventually convert to permanent AF—a critical distinction with major implications for prognosis and treatment success. Whilst clinical presentation varies widely (from overt performance failure to subclinical findings), diagnosis relies heavily on prolonged ECG monitoring to capture episodes and establish their frequency and duration, making current diagnostic tools inadequate for reliable detection in many cases. The authors highlight significant potential in adapting human cardiac monitoring technologies and automated ECG analysis algorithms to equine medicine, suggesting that such advances could substantially improve early detection and enable timely intervention to prevent progression to irreversible permanent arrhythmia.
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Practical Takeaways
- •Unexplained performance loss or reduced fitness in horses warrants cardiac evaluation including auscultation and ECG; subtle cases may require long-term monitoring to confirm pAF diagnosis
- •Early detection and treatment of paroxysmal AF is important because untreated episodes can lead to permanent atrial fibrillation and chronic performance issues
- •Consider adopting newer long-term ECG monitoring technologies adapted from human medicine to improve diagnostic capability and capture intermittent arrhythmias
Key Findings
- •Paroxysmal atrial fibrillation is the most common arrhythmia in horses and can present with symptoms ranging from sudden loss of racing performance to no clinical signs
- •Long-term ECG monitoring is essential for diagnosing pAF and understanding the duration and frequency of episodes
- •Untreated pAF may promote electrical, functional and structural myocardial remodeling that can progress to permanent AF
- •Human cardiac monitoring systems and computational ECG analysis have potential applications for improving equine cardiac diagnostics