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Home / Equine Research Bank / J Vet Intern Med / Associations between postrace atrial fibrillation and measur...
Journal of veterinary internal medicine2023; 37(6); 2573-2583; doi: 10.1111/jvim.16878

Associations between postrace atrial fibrillation and measures of performance, racing history and airway disease in horses.

Abstract: Atrial fibrillation (AF) is the most common performance limiting arrhythmia in racehorses. High dose exercise and airway disease promote AF in humans. Few studies have investigated epidemiological factors associated with AF in horses. Objective: Explore variables relating to performance, exercise volume and postrace endoscopic findings in horses with AF. Methods: A total of 164 horses with poor race performance and postrace AF were compared to 321 horses with poor performance without AF (PP) and 314 horses performing to expectation (TE). Methods: Horse-level and race-level variables for horses racing in Australia and Hong Kong from 2009 to 2021 were compared using univariable and multivariable logistic regression. Postrace endoscopic exercise-induced pulmonary hemorrhage (EIPH) and tracheal mucus accumulation (TMA) grades for AF and PP horses were compared using chi-squared analysis. Results: Variables that were significant in the multivariable model of AF compared to TE were distance (lengths) behind the winner, (odds ratio [OR]; 95% confidence interval [95% CI], 1.41 [1.32-1.51], P < .0001), cumulative prize money per start before the event (OR [95% CI] 1.02 [1.01-1.03], P = .01) and age (OR [95% CI] 0.72 [0.55-0.92], P = .01). More AF horses had EIPH grade ≥ 3 (23/109; 21.1%) than PP horses (7/213; 3.3%; OR [95%CI] 7.9 [3.3-20.2], P < .0001). Conclusions: Acute race performance was substantially impaired by AF but career earnings before the event were not inferior. Exercise volume did not promote AF. Higher grades of EIPH found in AF horses suggests a mechanistic relationship between these conditions.
© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
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Publication Date: 2023-09-23 PubMed ID: 37740606PubMed Central: PMC10658555DOI: 10.1111/jvim.16878Google Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research investigates the relationship between instances of poor race performance due to atrial fibrillation (AF), a common arrhythmia in racehorses, and factors such as performance variables, exercise levels, and endoscopic findings post-race. The study finds that not only is AF linked significantly to poorer race performance, but also to higher occurrences of exercise-induced pulmonary hemorrhage (EIPH), suggesting a possible physiological correlation between these conditions.

Research Scope and Methodology

  • The study focuses on a total of 164 horses that had poor post-race performance coupled with AF, comparing them with 321 horses with poor performance (PP) without AF and 314 horses that performed as expected (TE).
  • These comparisons were made based on horse-level and race-level variables for horse races in Australia and Hong Kong from 2009 to 2021.
  • A combination of univariable and multivariable logistic regression was used to compare the variables. Additionally, endoscopically diagnosed conditions such as exercise-induced pulmonary hemorrhage (EIPH) and tracheal mucus accumulation (TMA) in horses with AF and poor performance were compared using chi-squared analysis.

Key Findings

  • The multivariable model of AF in comparison to expected performance indicated significant variables like distance behind the winner, cumulative prize money before the event, and the horse’s age.
  • Most horses with AF had a higher grade of EIPH than horses without AF, indicating a potential mechanical relationship between AF and this type of pulmonary hemorrhage.

Conclusions

  • The research concludes that AF significantly impairs race performance in horses. However, it was found that career earnings of these horses before the instance of AF were not lower, suggesting that AF is not necessarily a result of exertion or exercise volume.
  • The higher frequency of EIPH in horses with AF suggests a connection between these conditions, hinting at a physiological correlation that could guide further epidemiological studies in equine health and performance.

Cite This Article

APA
Nath LC, Elliott A, La Gerche A, Weir J, Forbes G, Thomas G, Franklin S. (2023). Associations between postrace atrial fibrillation and measures of performance, racing history and airway disease in horses. J Vet Intern Med, 37(6), 2573-2583. https://doi.org/10.1111/jvim.16878

Publication

Journal of veterinary internal medicine
ISSN: 1939-1676
NlmUniqueID: 8708660
Country: United States
Language: English
Volume: 37
Issue: 6
Pages: 2573-2583

Researcher Affiliations

Nath, Laura C
  • University of Adelaide, Roseworthy, Australia.
Elliott, Adrian
  • University of Adelaide, Adelaide, Australia.
La Gerche, Andre
  • Baker Heart and Diabetes Institute, Melbourne, Australia.
Weir, Joe
  • Hong Kong Jockey Club, Hong Kong.
Forbes, Grace
  • Racing Victoria, Melbourne, Australia.
Thomas, Gijo
  • University of Adelaide, Adelaide, Australia.
Franklin, Samantha
  • University of Adelaide, Roseworthy, Australia.

MeSH Terms

  • Humans
  • Horses
  • Animals
  • Atrial Fibrillation / etiology
  • Atrial Fibrillation / veterinary
  • Physical Conditioning, Animal / adverse effects
  • Horse Diseases / etiology
  • Lung Diseases / veterinary
  • Running
  • Hemorrhage / veterinary

Grant Funding

  • Racing Victoria

Conflict of Interest Statement

Authors declare no conflict of interest.

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