Cardiac arrhythmia prevalence and risk factors in 24-h electrocardiograms of sedentary horses.
Abstract: Cardiac arrhythmias are common in horses, but their clinical relevance remains controversial. Objective: To describe prevalence and identify risk factors for arrhythmias that may warrant additional screening in a sedentary mixed-breed population of horses. Methods: Prospective cross-sectional. Methods: Ninety-four clinically healthy, university-owned, sedentary horses underwent 24-h ambulatory electrocardiograms and echocardiograms. Potential risk factors were recorded for all horses. Affected individuals were defined as those with >1 supraventricular premature complex/h or with any ventricular premature complexes for risk factor analysis. Forward stepwise logistic regression was used to identify factors associated with the presence of arrhythmia. The p value <0.15 was considered significant in univariable screening and p ≤ 0.05 was considered significant overall. Results: During recording, 92.6% (87/94) of horses experienced an arrhythmia. Supraventricular premature complexes were present in 86.2% (81/94) of the horses, and ventricular complexes were present in 24.5% (23/94) of the horses. Of the sample, 38.3% (36/94) were considered affected by arrhythmias. Increased heart girth score was associated with detection of arrhythmias (OR 1.06, 95% CI 1-1.12, p = 0.05) and age was retained in the final model as a confounder. Conclusions: The study sample included a limited range of body condition scores and number of stallions for risk factor analysis. Conclusions: Arrhythmias occurred with high frequency in this group of horses despite no known history or clinical signs of cardiovascular disease. Increased heart girth is a potential risk factor for arrhythmia in the horse.
© 2025 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Publication Date: 2025-07-18 PubMed ID: 40679167DOI: 10.1111/evj.14543Google Scholar: Lookup
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Summary
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The research article investigates the occurrence and possible risk factors associated with cardiac arrhythmias (irregular heartbeat) in sedentary, mixed-breed horses that are otherwise healthy.
Objective
The primary goals of the study were to:
- Describe the prevalence of arrhythmia in a sedentary population of mixed breed horses
- Identify potential risk factors that might necessitate additional screening for arrhythmia in this population
Methods
- A cross-sectional study was conducted where 94 clinically healthy, university-owned, sedentary horses were monitored via 24-hour ambulatory electrocardiograms and echocardiograms
- Potential risk factors were recorded for all horses, and those exhibiting more than one supraventricular premature complex per hour or any ventricular premature complexes were defined as affected
- Stepwise logistic regression was used to identify factors that might be associated with the presence of arrhythmia
- In univariable screening, p-value less than 0.15 was considered significant, and overall significance was pegged at p ≤ 0.05
Results
- Almost all the horses experienced an arrhythmia (92.6%) during recording
- The majority had supraventricular premature complexes (86.2%) while fewer had ventricular complexes (24.5%)
- A high percentage (38.3%) were designated as affected by arrhythmia
- Increased heart girth, or the circumference of the horses’ chests, was positively associated with detection of arrhythmia with an odds ratio (OR) of 1.06 and a significant p-value (p = 0.05)
- Age was kept in the statistical model as a confounder or potentially influencing variable
Conclusion
- The study concluded that arrhythmias are highly prevalent in this group of horses despite no previous evidence or symptoms of cardiovascular disease
- Increased heart girth was identified as a potential risk factor for arrhythmia in horses
- The limitations of the study include a limited range of body condition scores and number of stallions included in the sample
Cite This Article
APA
Maas LT, Louie EW, Finno CJ, Donnelly CG, Stern JA, Hill AE, Morgan JM.
(2025).
Cardiac arrhythmia prevalence and risk factors in 24-h electrocardiograms of sedentary horses.
Equine Vet J.
https://doi.org/10.1111/evj.14543 Publication
Researcher Affiliations
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
- Department of Population Health & Reproduction, School of Veterinary Medicine, University of California, Davis, California, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA.
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA.
- California Animal Health and Food Safety Lab, Davis, California, USA.
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA.
Grant Funding
- 20-25 / UC Davis Center for Equine Health
- Morris Animal Foundation
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