Occurrence of cardiac arrhythmias in Standardbred racehorses.
Abstract: Cardiac arrhythmias are a recognised but poorly characterised problem in the Standardbred racehorse. Frequency data could aid the development of cardiac arrhythmia screening programmes. Objective: To characterise the occurrence of cardiac arrhythmias in Standardbreds prior to racing and in the late post race period using a handheld, noncontinuous recording device. Methods: Prospective, observational study, convenience sampling. Methods: Noncontinuous electrocardiographic recordings were obtained over a 12 week period from Standardbred horses competing at a single racetrack. Electrocardiograms were obtained before racing and between 6 and 29 min after the race using a handheld recording device. Prevalence of arrhythmias was calculated for all horses and overall frequency of arrhythmias was calculated for race starts and poor performers. Univariate logistic regression analysis was used to identify risk factors for cardiac arrhythmias. Results: A total of 8657 electrocardiogram recordings were obtained from 1816 horses. Six horses had atrial fibrillation after racing (prevalence = 0.11%, frequency = 0.14%), one horse had supraventricular tachycardia before racing (prevalence = 0.06%, frequency = 0.02%), and 2 horses had ventricular tachyarrhythmias after racing (prevalence = 0.06%, frequency = 0.05%). The frequency of atrial fibrillation among race starts with poor performance was 1.3-2.0%. Increasing age was a significant risk factor for the presence of atrial premature contractions before racing and atrial fibrillation and ventricular ectopy after racing. Conclusions: Both physiological and pathological cardiac arrhythmias can be detected in apparently healthy Standardbred horses in the prerace and late post race period using noncontinuous recording methods. Future studies should examine cumulative training or racing hours as a risk factor for cardiac arrhythmia. The prevalence and frequency information may be useful for track veterinarians and regulatory personnel following trends in cardiac arrhythmias.
© 2014 EVJ Ltd.
Publication Date: 2014-07-17 PubMed ID: 24819401DOI: 10.1111/evj.12299Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
- Age Factors
- Athletic Horses
- Cardiac Arrhythmias
- Cardiovascular Health
- Clinical Study
- Diagnosis
- Diagnostic Technique
- Disease Diagnosis
- Disease Prevalence
- Electrocardiography
- Equine Health
- Exercise Physiology
- Heart
- Horse Racing
- Horse Training
- Observational Study
- Physiology
- Risk Factors
- Standardbred Horses
- Veterinary Medicine
- Veterinary Research
Summary
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This research studied the occurrence of heart rhythm disorders, known as cardiac arrhythmias, in a specific breed of racehorses called Standardbreds. The research team used handheld devices to record the heart rhythms before and after races over a 12-week period. They found that older age was a significant risk factor for these heart conditions. The findings may be useful in monitoring trends and developing screening programmes for this issue.
Methodology
- The researchers conducted a prospective, observational study implementing convenience sampling—a non-random sample based on easy availability and accessibility.
- The team collected non-continuous electrocardiographic (ECGs) recordings over a 12-week period from Standardbred horses participating at a single racetrack. ECGs measure the electrical signals in the heart, thus showing any irregularities in the heart’s rhythm.
- ECGs were taken before and between 6 and 29 minutes after each race using a handheld recording device.
- Using this data, the team calculated the prevalence (how common it is) and frequency (how often it happened) of cardiac arrhythmias for all horses.
- Univariate logistic regression analysis was employed to identify risk factors for heart rhythm disorders. This method looks at the connection between a single variable, for example, the age of the horse, and the likelihood of heart rhythm disorders occurring.
Results
- A total of 8,657 ECGs were recorded from 1,816 horses.
- Some instances of cardiac arrhythmias were identified. Six horses experienced atrial fibrillation (heart quivering instead of beating properly) after racing, one horse presented supraventricular tachycardia (fast heart beat that begins above the heart’s lower chambers) before the race, and two horses had ventricular tachyarrhythmias (fast, irregular heartbeats) after racing.
- An important finding was that older age was a significant risk factor for atrial premature contractions (extra, abnormal heartbeat) before racing and for atrial fibrillation and ventricular ectopy (irregular heartbeats) after racing.
Conclusions
- The researchers found that both physiological (related to the normal function of the body) and pathological (related to disease) cardiac arrhythmias can appear in seemingly healthy Standardbred racehorses both before and after racing.
- The recommendation was made for future studies to examine the influence of cumulative hours spent in training and racing as a potential risk factor for cardiac arrhythmia.
- The data on prevalence and frequency could be valuable for veterinarians and regulatory personnel in tracking trends in heart rhythm disorders among Standardbred racehorses and in developing screening programs for these disorders.
Cite This Article
APA
Slack J, Boston RC, Soma LR, Reef VB.
(2014).
Occurrence of cardiac arrhythmias in Standardbred racehorses.
Equine Vet J, 47(4), 398-404.
https://doi.org/10.1111/evj.12299 Publication
Researcher Affiliations
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, USA.
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, USA.
MeSH Terms
- Aging
- Animals
- Arrhythmias, Cardiac / diagnosis
- Arrhythmias, Cardiac / veterinary
- Electrocardiography / veterinary
- Female
- Horse Diseases / diagnosis
- Horses
- Male
- Prospective Studies
- Risk Factors
- Sports
- Temperature
Citations
This article has been cited 18 times.- Kapusniak A, Lara NM, Hitchens PL, Bailey S, Nath L, Franklin S. Use of Artificial Intelligence to Detect Cardiac Rhythm Disturbances in Athletes: A Scoping Review. J Vet Intern Med 2025 Nov-Dec;39(6):e70257.
- Nissen SD, Bastrup JA, Haugaard SL, Marion-Knudsen R, Schneider M, Kjeldsen ST, Carstensen H, Hopster-Iversen C, Nattel S, Jepps TA, Buhl R. Horse model of spontaneous atrial fibrillation share proteomic changes with humans. Sci Rep 2025 Aug 28;15(1):31694.
- Kjeldsen ST, Nissen SD, Christensen NC, Haugaard SL, Schneider MJ, Vinther Z, Sattler SM, Carstensen H, Jøns C, Hopster-Iversen C, Buhl R. Validation and clinical application of implantable loop recorders for diagnosis of atrial fibrillation in horses. Equine Vet J 2025 Mar;57(2):449-458.
- Nath LC, Saljic A, Buhl R, Elliott A, La Gerche A, Ye C, Schmidt Royal H, Lundgren Virklund K, Agbaedeng TA, Stent A, Franklin S. Histological evaluation of cardiac remodelling in equine athletes. Sci Rep 2024 Jul 19;14(1):16709.
- Nath LC, Elliott A, La Gerche A, Weir J, Forbes G, Thomas G, Franklin S. Associations between postrace atrial fibrillation and measures of performance, racing history and airway disease in horses. J Vet Intern Med 2023 Nov-Dec;37(6):2573-2583.
- White R, Nath L, Hebart M, Franklin S. Assessment of P Wave Indices in Healthy Standardbred Horses. Animals (Basel) 2023 Mar 16;13(6).
- Kjeldsen ST, Nissen SD, Buhl R, Hopster-Iversen C. Paroxysmal Atrial Fibrillation in Horses: Pathophysiology, Diagnostics and Clinical Aspects. Animals (Basel) 2022 Mar 10;12(6).
- Ter Woort F, Dubois G, Tansley G, Didier M, Verdegaal L, Franklin S, Van Erck-Westergren E. Validation of an equine fitness tracker: ECG quality and arrhythmia detection. Equine Vet J 2022 Feb 9;55(2):336-43.
- Hellings IR, Skjerve E, Karlstam E, Valheim M, Ihler CF, Fintl C. Racing-associated fatalities in Norwegian and Swedish harness racehorses: Incidence rates, risk factors, and principal postmortem findings. J Vet Intern Med 2022 Mar;36(2):778-786.
- Buhl R, Hesselkilde EM, Carstensen H, Hopster-Iversen C, van Loon G, Decloedt A, Van Steenkiste G, Marr CM, Reef VB, Schwarzwald CC, Mitchell KJ, Nostell K, Nogradi N, Nielsen SS, Carlson J, Platonov PG. Atrial fibrillatory rate as predictor of recurrence of atrial fibrillation in horses treated medically or with electrical cardioversion. Equine Vet J 2022 Nov;54(6):1013-1022.
- Alberti E, Stucchi L, Lo Feudo CM, Stancari G, Conturba B, Ferrucci F, Zucca E. Evaluation of Cardiac Arrhythmias before, during, and after Treadmill Exercise Testing in Poorly Performing Standardbred Racehorses. Animals (Basel) 2021 Aug 16;11(8).
- Nath LC, Elliott AD, Weir J, Curl P, Rosanowski SM, Franklin S. Incidence, recurrence, and outcome of postrace atrial fibrillation in Thoroughbred horses. J Vet Intern Med 2021 Mar;35(2):1111-1120.
- Cherdchutham W, Koomgun K, Singtoniwet S, Wongsutthawart N, Nontakanun N, Wanmad W, Petchdee S. Assessment of cardiac variables using a new electrocardiography lead system in horses. Vet World 2020 Jun;13(6):1229-1233.
- Buhl R, Hesselkilde EM, Carstensen H, Fenner MF, Jespersen T, Tfelt-Hansen J, Michael Sattler S. Detection of atrial fibrillation with implantable loop recorders in horses. Equine Vet J 2021 Mar;53(2):397-403.
- Welch-Huston B, Durward-Akhurst S, Norton E, Ellingson L, Rendahl A, McCue M. Comparison between smartphone electrocardiography and standard three-lead base apex electrocardiography in healthy horses. Vet Rec 2020 Oct 31;187(9):e70.
- Alexeenko V, Fraser JA, Dolgoborodov A, Bowen M, Huang CL, Marr CM, Jeevaratnam K. The application of Lempel-Ziv and Titchener complexity analysis for equine telemetric electrocardiographic recordings. Sci Rep 2019 Feb 22;9(1):2619.
- Buhl R, Carstensen H, Hesselkilde EZ, Klein BZ, Hougaard KM, Ravn KB, Loft-Andersen AV, Fenner MF, Pipper C, Jespersen T. Effect of induced chronic atrial fibrillation on exercise performance in Standardbred trotters. J Vet Intern Med 2018 Jul;32(4):1410-1419.
- da Costa CF, Samesima N, Pastore CA. Cardiac Mean Electrical Axis in Thoroughbreds-Standardization by the Dubois Lead Positioning System. PLoS One 2017;12(1):e0169619.
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