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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; 14:16709. [PMID: 39030282 PMCID: PMC11271503 DOI: 10.1038/s41598-024-67621-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 07/14/2024] [Indexed: 07/21/2024] Open
Abstract
Approximately 1-2 per 100,000 young athletes die from sudden cardiac death (SCD) and extreme exercise may be associated with myocardial scar and arrhythmias. Racehorses have a high prevalence of atrial fibrillation (AF) and SCD but the presence of myocardial scar and inflammation has not been evaluated. Cardiac tissues from the left (LAA) and right (RAA) atrial appendages, left ventricular anterior (LVAPM) and posterior (LVPPM) papillary muscles, and right side of the interventricular septum (IVS-R) were harvested from racehorses with sudden cardiac death (SCD, n = 16) or other fatal injuries (OFI, n = 17), constituting the athletic group (ATH, n = 33), and compared to sedentary horses (SED, n = 10). Horses in the ATH group had myocyte hypertrophy at all sites; increased fibrosis at all sites other than the LAA; increased fibroblast infiltration but a reduction in the overall extracellular matrix (ECM) volume in the RAA, LVAPM, and IVS-R compared to SED horses. In this horse model, athletic conditioning was associated with myocyte hypertrophy and a reduction in ECM. There was an excess of fibrocyte infiltration and focal fibrosis that was not present in non-athletic horses, raising the possibility of an exercise-induced pro-fibrotic substrate.
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Affiliation(s)
- L C Nath
- University of Adelaide, Adelaide, Australia.
| | - A Saljic
- University of Copenhagen, Copenhagen, Denmark
| | - R Buhl
- University of Copenhagen, Copenhagen, Denmark
| | - A Elliott
- University of Adelaide, Adelaide, Australia
| | - A La Gerche
- St Vincents Institute Medical Research, Fitzroy, Australia
| | - C Ye
- University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - A Stent
- University of Melbourne, Parkville, Australia
| | - S Franklin
- University of Adelaide, Adelaide, Australia
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2
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Hansen S, Otten ND, Nissen SD, Carstensen H, Hopster-Iversen C, Fjeldborg J, Staun SH, Fenner M, Hesselkilde EM, Buhl R. Atrial fibrillation as a risk factor for exercise-induced pulmonary haemorrhage following a standardised exercise test. Equine Vet J 2024; 56:552-561. [PMID: 37654233 DOI: 10.1111/evj.13995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/17/2023] [Indexed: 09/02/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) has been proposed as a risk factor for exercise-induced pulmonary haemorrhage (EIPH) due to increased pressure in the left atrium. OBJECTIVE To evaluate if AF was associated with EIPH following a standardised exercise test (SET) to fatigue. STUDY DESIGN Two-arm controlled experiment. METHODS Ten untrained Standardbred mares mean (standard deviation [SD]) age 6 (2) years performed a SET on the treadmill in sinus rhythm (SR) (SET1) and 25-44 days after induction of self-sustained AF (SET2). AF was induced by tachypacing using a pacing device. Endoscopy, including tracheal wash and bronchoalveolar lavage (BAL), was performed 48-72 h before and 24 h after the two SETs. In addition, endoscopic grading of tracheal blood was performed 2 h after each SET. RESULTS After SET1, none of the horses showed blood in the trachea, and two horses showed erythrophagocytosis. Following SET2, two horses had grade 1 blood in the trachea and free erythrocytes and erythrophagocytosis in the BAL, while another two horses had erythrophagocytosis in the BAL. In SET2, the overall performance on the treadmill was decreased with a lower maximum velocity (SET1 10.3 ± 0.8 m/s vs. SET2 8.9 ± 0.9 m/s, p = 0.004), a higher heart rate (284 ± 21 vs. 221 ± 18 bpm, p = 0.003) and more abnormal QRS complexes (p < 0.001) compared with SET1. CONCLUSIONS Two horses showed signs of EIPH, resulting in visible blood in the trachea, when exercising in AF compared with SR. However, a possible link between EIPH, pulmonary pressure and AF needs to be further elucidated.
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Affiliation(s)
- Sanni Hansen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Nina D Otten
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Sarah D Nissen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Charlotte Hopster-Iversen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Julie Fjeldborg
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Sophie H Staun
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Merle Fenner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Eva M Hesselkilde
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
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Durando MM, Slack J, Birks E, Belcher C, Kohn C. Premature depolarisations in horses competing in United States Eventing Association and Fédération Equestre Internationale-sanctioned 3-day events. Equine Vet J 2024; 56:59-68. [PMID: 37248851 DOI: 10.1111/evj.13948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 05/04/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Injuries and sudden death during the cross-country (XC) phase of eventing have raised interest in the frequency and types of cardiac arrhythmias occurring in these equine athletes. OBJECTIVES To characterise the frequency and types of rhythm disturbances and examine possible risk factors for premature depolarisations (PDs) occurring during the XC phase of United States Eventing Association (USEA) and Fédération Equestre Internationale (FEI)-sanctioned events. STUDY DESIGN Prospective, cross-sectional study. METHODS Continuous electrocardiographic (ECG) recordings were obtained from horses prior to, during and immediately following the XC competition. Physiological rhythms pre-XC were included in the arrhythmia group for analysis. The frequency of PDs was calculated for all horses, as well as by division. PDs were categorised by complexity (singles, couplets, triplets, complex) and variably grouped for statistical analysis. Multiple logistic regression was used to identify risk factors for the presence of specific cardiac arrhythmia groupings during XC. RESULTS PDs were identified in 42/75 horses (56% [45, 67]) during XC. Horses competing in the upper divisions of eventing had higher odds for having any PD during XC compared to the lower divisions (OR = 17.5 [4.3, 72.01], p = 0.006). The amount of time the heart rate (HR) was greater than 199 beats per minute (BPM) was associated with more complex arrhythmias (triplets, salvos and tachyarrhythmias) (OR = 1.01 [1.0, 1.02], p = 0.005). An arrhythmia at rest (physiological or PD) was associated with arrhythmia in the early recovery period (OR = 3.5 [1.1, 10.8], p = 0.03). MAIN LIMITATIONS Convenience sampling and technical challenges of continuous ECG recordings under competition settings limited the number of enrollments. CONCLUSIONS PDs were seen in a high percentage of horses during the XC competition. Upper levels and time the HR was greater than 199 BPM were related to PD presence and complexity.
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Affiliation(s)
- Mary M Durando
- Equine Sports Medicine Consultants, Newark, Delaware, USA
| | - Joann Slack
- New Bolton Center, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Eric Birks
- Equine Sports Medicine Consultants, Newark, Delaware, USA
| | - Carolyn Belcher
- Georgia Department of Natural Resources, Coastal Resources Division, Brunswick, Georgia, USA
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Massie SL, Bezugley RJ, McDonald KJ, Léguillette R. Training vs. racing: A comparison of arrhythmias and the repeatability of findings in Thoroughbred Chuckwagon racehorses. Vet J 2023; 300-302:106040. [PMID: 37898456 DOI: 10.1016/j.tvjl.2023.106040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 10/30/2023]
Abstract
Arrhythmias are commonly reported in exercising horses, however due to regulatory constraints electrocardiograms (ECGs) are acquired during training but not competition, raising questions about the repeatability of findings. The aims were (1) compare training and competition arrhythmias and (2) describe the repeatability of arrhythmias during maximal-intensity exercise. A convenience sample of 52 healthy Thoroughbreds (aged 8.7 ± 2.5 years) competing in the World Professional Chuckwagon Association were obtained, totaling 152 training or competition ECGs (2-7 ECGs/horse). Speed, heart rate (HR) and arrhythmias (supraventricular premature complex, SVPC; ventricular premature complex, VPC) were examined. Pre- and post-recovery (approximately 6 min) blood samples measured lactate and high-sensitivity troponin-T. Training and competition arrythmias were compared (Friedman's test) and reliability of repeated ECGs assessed (intraclass correlation; P < 0.05). Training vs. competition: Forty horses had clean tracing from training and competition (n = 80 ECGs); the number and type of arrhythmias were not different. In training, VPCs were present in 7/40 horses (median [interquartile range, IQR]/ECG; range; 0 [0,0]; 0-4) and 9/40 horses (0 [0,0]; 0-5) in active-recovery. In competition, VPCs were present in 7/40 horses (0 [0,0]; 0-8) and 8/40 horses (0 [0,0]; 0-5) in active-recovery. Arrhythmias were primarily single premature complexes. Training and competition speed, HR, lactate and troponin-T did not differ however, sampling was too early for peak serum Troponin-T levels. Repeatability: total arrhythmias between serial ECGs did not differ. The reliability to detect SVPCs and VPCs was poor to moderate, and poor, respectively. Overall, the total number of arrhythmias was repeatable, but the reliability of arrhythmia type was poor to moderate.
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Affiliation(s)
- S L Massie
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - R J Bezugley
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - K J McDonald
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - R Léguillette
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
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Hammond A, Sage W, Hezzell M, Smith S, Franklin S, Allen K. Heart rate variability during high-speed treadmill exercise and recovery in Thoroughbred racehorses presented for poor performance. Equine Vet J 2023; 55:727-737. [PMID: 36537845 DOI: 10.1111/evj.13908] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
BACKGROUND Heart rate variability (HRV) analysis measures the inter-beat interval variation of successive cardiac cycles. Measurement of these indices has been used to assess cardiac autonomic modulation and for arrhythmia identification in exercising horses. OBJECTIVES To report HRV indices during submaximal exercise, strenuous exercise and recovery, and explore relationships with clinical conditions (arrhythmias, lameness, equine gastric ulcer syndrome [EGUS], lower airway inflammation and upper respiratory tract obstructions [URTOs]) in Thoroughbred racehorses. STUDY DESIGN Retrospective, observational cross-sectional study. METHODS One hundred and eighty Thoroughbred horses underwent a treadmill exercise test with simultaneous electrocardiographic recording. Time-domain HRV indices (standard deviation of the R-R interval [SDRR]; root mean square of successive differences [RMSSD]) were derived for submaximal and strenuous exercise and recovery segments. Clinical conditions (arrhythmia [during each phase of exercise], lameness, EGUS, lower airway inflammation and URTO) were assigned to binary categories for statistical analysis. Relationships between selected HRV indices and the clinical conditions were explored using linear regression models. RESULTS During submaximal exercise, lameness was associated with decreased logRMSSD (B = -0.19 95% confidence interval [CI] -0.31 to -0.06, p = 0.006) and arrhythmia was associated with increased logRMSSD (B = 0.31 95% CI 0.01-0.608, p = 0.04). During strenuous exercise, arrhythmia was associated with increased HRV indices (logSDRR B = 0.51 95% CI 0.40-0.62, p < 0.001; RMSSD B = 0.60 95% CI 0.49-0.72, p < 0.001). During recovery, arrhythmia was associated with increased HRV indices (logSDRR B = 0.51 95% CI 0.40-0.62, p < 0.001, logRMSSD B = 0.60 95% CI 0.49-0.72, p < 0.001). MAIN LIMITATIONS The main limitations of this retrospective study were that not every horse had the full range of clinical testing, therefore some horses may have had undetected abnormalities. CONCLUSIONS The presence of arrhythmia increased HRV in both phases of exercise and recovery. Lameness decreased HRV during submaximal exercise.
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Affiliation(s)
- Anna Hammond
- Bristol Veterinary School, University of Bristol, Bristol, UK
- Perth Equine Vets, Perth, UK
| | - William Sage
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Melanie Hezzell
- Bristol Veterinary School, University of Bristol, Bristol, UK
| | - Sarah Smith
- Bristol Veterinary School, University of Bristol, Bristol, UK
- B&W Equine, Gloucestershire, UK
| | - Samantha Franklin
- School of Animal & Veterinary Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Kate Allen
- Bristol Veterinary School, University of Bristol, Bristol, UK
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Santosuosso E, David F, Massie S, Filho SA, McCrae P, Johnson S, Leguillette R. Frequency of cardiac arrhythmias in horses during straight and untethered swimming. Equine Vet J 2023; 55:738-746. [PMID: 36273248 DOI: 10.1111/evj.13895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 10/02/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Cardiac arrhythmias have not been previously reported in horses while swimming. OBJECTIVES To describe the type and frequency of encountered arrhythmias during repetitive swimming cycles. STUDY DESIGN Descriptive observational study. METHODS Sixteen horses swam five pool lengths (75 m), each separated by an active recovery walk. Continuous electrocardiograms (ECGs) were recorded (n = 80) and analysed during the pre-swim, swim and active-recovery periods. Arrhythmias were categorised as sinus arrhythmia (SA), sinus block, sinus pause (compensatory and non-compensatory), second degree atrioventricular block (2AVB) for physiological arrhythmias, supraventricular premature depolarisation (SVPD) and ventricular premature depolarisation (VPD) for non-physiological arrhythmias. A linear mixed-effects model was used to examine the effects of repetitive swim lengths on arrhythmias and swimming parameters. Data were reported as median [interquartile range]. RESULTS Fifteen horses (94%) experienced at least one arrhythmia; however, the frequency remained low and 2AVB were only observed during the pre-swim period. The swimming heart rate (HR) was 162 bpm [141;173]. Sinus blocks, sinus pauses, SA, SVPD and VPD were all recorded at least once during swimming. Except for one VPD couplet, all premature depolarisations were isolated. During active-recovery, the HR was 105 bpm [103;106], with SA observed in 13 horses (81%), isolated SVPD in six horses (38%), sinus pause in one horse (6%) but no VPD present. MAIN LIMITATIONS Limited number of horses precluding population prevalence assessment. CONCLUSION AND CLINICAL IMPORTANCE High-quality underwater ECGs were acquired in swimming horses for the first time. The frequency of arrhythmias remained low and rare pathological arrhythmias were observed during repetitive swimming and active-recovery cycles. Swimming with active-recovery periods is not a high-risk cardio-arrhythmic exercise.
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Affiliation(s)
- Emma Santosuosso
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Florent David
- Equine Veterinary Medical Center, Member of Qatar Foundation, Doha, Qatar
| | - Shannon Massie
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Silvio A Filho
- Al Shaqab - Endurance Department, Member of Qatar Foundation, Doha, Qatar
| | - Persephone McCrae
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sarah Johnson
- Equine Veterinary Medical Center, Member of Qatar Foundation, Doha, Qatar
| | - Renaud Leguillette
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
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McCrae P, Spong H, Rutherford AA, Osborne V, Mahnam A, Pearson W. A Smart Textile Band Achieves High-Quality Electrocardiograms in Unrestrained Horses. Animals (Basel) 2022; 12:ani12233254. [PMID: 36496775 PMCID: PMC9740902 DOI: 10.3390/ani12233254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/16/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Electrocardiography (ECG) is an essential tool in assessing equine health and fitness. However, standard ECG devices are expensive and rely on the use of adhesive electrodes, which may become detached and are associated with reduced ECG quality over time. Smart textile electrodes composed of stainless-steel fibers have previously been shown to be a suitable alternative in horses at rest and during exercise. The objective of this study was to compare ECG quality using a smart textile girth band knit with silver and carbon yarns to standard adhesive silver/silver chloride (Ag/AgCl) electrodes. Simultaneous three-lead ECGs were recorded using a smart textile band and Ag/AgCl electrodes in 22 healthy, mixed-breed horses that were unrestrained in stalls. ECGs were compared using the following quality metrics: Kurtosis (k) value, Kurtosis signal quality index (kSQI), percentage of motion artifacts (%MA), peak signal amplitude, and heart rate (HR). Two-way ANOVA with Tukey’s multiple comparison tests was conducted to compare each metric. No significant differences were found in any of the assessed metrics between the smart textile band and Ag/AgCl electrodes, with the exception of peak amplitude. Kurtosis and kSQI values were excellent for both methods (textile mean k = 21.8 ± 6.1, median kSQI = 0.98 [0.92−1.0]; Ag/AgCl k = 21.2 ± 7.6, kSQI = 0.99 [0.97−1.0]) with <0.5% (<1 min) of the recording being corrupted by MAs for both. This study demonstrates that smart textiles are a practical and reliable alternative to the standard electrodes typically used in ECG monitoring of horses.
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Affiliation(s)
- Persephone McCrae
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Hannah Spong
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | | | - Vern Osborne
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Amin Mahnam
- Department of Research and Development, Myant Inc., Toronto, ON M9W 1B6, Canada
| | - Wendy Pearson
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada
- Correspondence:
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Nath L, Stent A, Elliott A, La Gerche A, Franklin S. Risk Factors for Exercise-Associated Sudden Cardiac Death in Thoroughbred Racehorses. Animals (Basel) 2022; 12:ani12101297. [PMID: 35625143 PMCID: PMC9137751 DOI: 10.3390/ani12101297] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 02/04/2023] Open
Abstract
Cardiac arrhythmias resulting in sudden cardiac death (SCD) are an important cause of racehorse fatalities. The objective of this study was to determine risk factors for SCD in Thoroughbreds by evaluating a sample with a policy of mandatory post-mortem following racing or training fatalities. Risk factors were compared between case horses with SCD (n = 57) and control horses with other fatal injury (OFI, n = 188) by univariable and multivariable logistic regression. Survival in years for horses with SCD was compared to OFI using the Kaplan−Meier method with log rank test. The following variables were most important in the multiple logistic model: Horses with SCD were more likely to die during training than during racing, SCD (42/57, 74%) vs. OFI (82/188, 44%; odds ratio [OR], 95% confidence interval [CI], 2.5, 1.2−5.4; p = 0.01), had fewer lifetime starts, median (interquartile range [IQR]), SCD (3.0 [0.0−9.0]) vs. OFI (9.0 [0.0−22.8]; OR, 95% CI, 0.96, 0.9−1.0; p = 0.02 and were less likely to be entire (uncastrated) males, SCD 9/57 (16%) vs. OFI (46/188, 25%; OR, 95% CI, 0.47, 0.1−0.9; p = 0.03). Survival in years (median (IQR)) for horses with SCD was 3.6 (3.1−4.4), which was shorter than OFI (4.5 [3.1−6.0], hazard ratio, 95%CI, 1.6,1.2−2.3; p < 0.001). SCD occurs more commonly in training than racing, which suggests exercise intensity is less important in precipitating this fatality. In this study, SCD occurred early in the careers of affected horses.
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Affiliation(s)
- Laura Nath
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy 5371, Australia;
- Correspondence:
| | - Andrew Stent
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee 3030, Australia;
| | - Adrian Elliott
- Centre for Heart Rhythm Disorders, University of Adelaide, Adelaide 5005, Australia;
| | - Andre La Gerche
- Baker Heart and Diabetes Institute, Melbourne 3004, Australia;
| | - Samantha Franklin
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy 5371, Australia;
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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; 36:778-786. [PMID: 35060194 PMCID: PMC8965266 DOI: 10.1111/jvim.16364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 01/03/2022] [Accepted: 01/07/2022] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND There are no reports on the number of fatalities or causes of death in the Norwegian and Swedish harness racehorses. OBJECTIVES The incidence rates (IRs), risk factors, and postmortem findings in horses that died or were euthanized associated with racing between 2014 and 2019 were investigated. ANIMALS Thirty-eight Standardbreds and 10 Norwegian-Swedish Coldblooded Trotters died or were euthanized associated with racing. A total of 816 085 race-starts were recorded. METHODS Incidence rates were calculated for both countries and horse breeds. Risk factors for sudden death were identified using a case-control logistic model. Postmortem examinations were performed in 43 horses. RESULTS The overall fatality IR was 0.059/1000 race-starts. Traumatic injuries accounted for 14.5%, while sudden death for 85.5% of fatalities. Only minor differences between countries and breeds were recorded. The number of starts within the last 30 days increased the risk of sudden death (5 starts odds ratio (OR) 228.80, confidence interval (CI) 10.9-4793). An opposite non-linear effect was observed in number of starts the last 180 days (>10 starts OR 0.12, CI 0.02-0.68). Seven horses were euthanized because of catastrophic injury. Acute circulatory collapse because of suspected cardiac or pulmonary failure or both was recorded in 30 horses, while major hemorrhage after vessel rupture was the primary cause of death in 10 cases. One horse collapsed and died but was not submitted for autopsy. CONCLUSIONS AND CLINICAL IMPORTANCE Comparatively low rates of catastrophic orthopedic fatalities were reported, while causes and IR of sudden death were similar to previous studies.
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Affiliation(s)
- Ingunn Risnes Hellings
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine and BiosciencesNorwegian University of Life SciencesÅsNorway
| | - Eystein Skjerve
- Department of Production Animal Clinical Sciences, Faculty of Veterinary Medicine and BiosciencesNorwegian University of Life SciencesÅsNorway
| | - Erika Karlstam
- Department of Pathology and Wildlife DiseasesThe Swedish National Veterinary InstituteUppsalaSweden
| | - Mette Valheim
- Department of Pathology and High‐Risk PathogensThe Norwegian Veterinary InstituteÅsNorway
| | - Carl Fredrik Ihler
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine and BiosciencesNorwegian University of Life SciencesÅsNorway
| | - Constanze Fintl
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine and BiosciencesNorwegian University of Life SciencesÅsNorway
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An Exploratory Study on Vectorcardiographic Identification of the Site of Origin of Focally Induced Premature Depolarizations in Horses, Part II: The Ventricles. Animals (Basel) 2022; 12:ani12050550. [PMID: 35268119 PMCID: PMC8908816 DOI: 10.3390/ani12050550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 01/15/2023] Open
Abstract
In human cardiology, the anatomical origin of ventricular premature depolarizations (VPDs) is determined by the characteristics of a 12-lead electrocardiogram (ECG). Former studies in horses had contradictory results regarding the diagnostic value of the 12-lead ECG and vectorcardiography (VCG), which results were attributed to the different cardiac conduction system in this species. The objective of this study was to determine if the anatomical origin of pacing-induced VPDs could be differentiated in horses based upon VCG characteristics. A 12-lead ECG was recorded in seven horses under general anesthesia while right and left ventricular endomyocardial pacing was performed (800−1000 ms cycle length) at the apex, mid and high septum and mid and high free wall, and at the right ventricular outflow tract. Catheter positioning was guided by 3D electro-anatomical mapping and echocardiography. A median complex, obtained from four consecutive complexes, was calculated for each pacing location and sinus rhythm. The VCG was calculated from the 12-lead ECG-derived median complexes using custom-made algorithms and was used to determine the initial and maximum electrical axes of the QRS complex. An ANOVA for spherical data was used to test if VCGs between each paced location and between pacing and sinus rhythm were significantly (p < 0.05) different. The model included the radius, azimuth and elevation of each electrical axis. Pacing induced significantly different initial and maximum electrical axes between different locations and between pacing and sinus rhythm. The current results suggest that VCG is a useful technique to identify the anatomical origin of ventricular ectopy in horses.
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ter Woort F, Dubois G, Tansley G, Didier M, Verdegaal E, Franklin S, Van Erck‐Westergren E. Validation of an equine fitness tracker: ECG quality and arrhythmia detection. Equine Vet J 2022; 55:336-343. [PMID: 35138653 PMCID: PMC10078706 DOI: 10.1111/evj.13565] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 01/16/2022] [Accepted: 02/02/2022] [Indexed: 12/01/2022]
Abstract
BACKGROUND Cardiac arrhythmias in exercising horses are the focus of much interest, both in terms of what is considered normal and potential associations with poor performance and sudden cardiac death. One barrier to performing large-scale studies is the lack of an easily applicable device, to allow recording of large numbers of high-quality exercising electrocardiograms (ECGs). The EquimetreTM is a new wearable device which records a single lead ECG, amongst other parameters. Validation of such wearable devices is essential before further studies are undertaken. OBJECTIVES To evaluate the quality of ECG using the EquimetreTM and compare arrhythmia detection during exercise with the reference TelevetTM system. STUDY DESIGN Prospective blinded clinical study. METHODS Simultaneous ECGs were recorded with both systems in 49 healthy horses during exercise. High intensity exercise (>40km/h) was performed by 29 racehorses, and lower intensity exercise for the remainder of the racehorses and show jumpers. Tracings were excluded if >10% artefact was present (duration of artefact relative to duration of exercise). For included ECGs, the duration of artefact was recorded and compared. ECGs were evaluated using Kubios premium software. Arrhythmia detection (yes/no) and arrhythmia classification (sinus arrhythmia, narrow complex of similar morphology to the sinus complexes or wide complex with a different morphology) were compared using Cohen's Kappa coefficient. RESULTS Nine TelevetTM ECGs and 3 EquimetreTM ECGs were excluded due to artefact >10%. TelevetTM ECGs included significantly more artefact during exercise than EquimetreTM ECGs (5% vs. 0.25% p<0.001). Arrhythmia analysis was performed on 38 horses' paired ECGs. The Kappa coefficient was excellent for arrhythmia detection (K=0.97) and arrhythmia classification (K=0.93). MAIN LIMITATIONS Relatively low numbers of horses with arrhythmias (n=21) were included. The ECG recordings only provided one lead, making arrhythmia classification challenging in some cases. CONCLUSIONS The Equimetre device provides a reliable ECG for arrhythmia detection during exercise. This system may be useful clinically and for future large-scale investigations into the occurrence and significance of exercising arrhythmias.
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Affiliation(s)
| | | | - Grace Tansley
- Equine Health and Performance CenterUniversity of Adelaide, Roseworthy CampusRoseworthySouth AustraliaAustralia
| | | | - Elisabeth‐Lidwien Verdegaal
- Equine Health and Performance CenterUniversity of Adelaide, Roseworthy CampusRoseworthySouth AustraliaAustralia
| | - Samantha Franklin
- Equine Health and Performance CenterUniversity of Adelaide, Roseworthy CampusRoseworthySouth AustraliaAustralia
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12
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Jago R, Blissitt K. How to record a good quality ECG in horses. IN PRACTICE 2022. [DOI: 10.1002/inpr.167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Nath LC, Forbes G, Elliott AD, Tomren V, Ryan A, Franklin SH. Application of an electrocardiography device (iECG) for heart rhythm analysis after exercise in Thoroughbred horses. Aust Vet J 2021; 100:114-120. [PMID: 34859419 DOI: 10.1111/avj.13137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 10/08/2021] [Accepted: 11/14/2021] [Indexed: 12/01/2022]
Abstract
AliveCor is a smartphone electrocardiography device (iECG) providing automated heart rate (HR) and rhythm determination. Atrial fibrillation (AF) in horses often is paroxysmal and rapid ECG acquisition is needed for diagnostic confirmation. iECGs were collected post-race from 15 horses with AF and 64 horses in sinus rhythm (SR). Results of manual assessment were compared to 3 commercial algorithms for HR and rhythm. Agreement between manually derived HR (HRM ) and HR derived by the AliveECG Vet (HRVET ) and Kardia version-1 (KV1 HR) and Kardia advanced (KADV HR) algorithms was quantified by the Bland-Altman limits of agreement test. Agreement between manual rhythm classification and KV1 and KADV algorithms for AF and SR was calculated by the Kappa statistical coefficient. The agreement (bias, 95% limits), between HRM and HRVET was 7.1 BPM (-29 to 43) in AF and -4.2 BPM (-38 to 30) in SR, between HRM and KV1 HR, was -0.3 BPM (-31 to 30) in AF and 0.2 BPM (-3 to 4) in SR, and between HRM and KADV HR was 7.0 BPM (-29 to 43) in AF and 0.2 BPM (-3.9 to 4.2) in SR. Agreement between manual rhythm classification and KV1 was 0.36 (0.13-0.59), and KADV was 0.84 (0.68-0.99). Sensitivity and specificity for identification of AF and SR of the KV1 algorithm were 60, 100% and 83, 100%, respectively, and of KADV was 87, 100% and 93, 100% respectively. The Kardia algorithms improved precision for HR determination in SR but not AF. The advanced algorithm accurately distinguished between AF and SR. The iECG is suitable for recording episodes of AF following exercise.
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Affiliation(s)
- L C Nath
- University of Adelaide, Roseworthy, South Australia, Australia
| | - G Forbes
- Racing Victoria, Flemington, Victoria, Australia
| | - A D Elliott
- University of Adelaide, Adelaide, South Australia, Australia
| | - V Tomren
- Racing Victoria, Flemington, Victoria, Australia
| | - A Ryan
- University of Adelaide, Roseworthy, South Australia, Australia
| | - S H Franklin
- University of Adelaide, Roseworthy, South Australia, Australia
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Haughan J, Manriquez M, Cohen N, Robinson M, de Solis CN. Comparison of novel wearable cardiac monitors to yield accurate exercising ECG and heart rate data in horses. COMPARATIVE EXERCISE PHYSIOLOGY 2021. [DOI: 10.3920/cep200080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exercise associated deaths (EADs) in horses are a problem for the equestrian industry. Sudden death (SD) is responsible for approximately 20% of EADs. The underlying cause of SD is suspected to be cardiovascular disease but often cannot be determined post-mortem. User-friendly cardiac monitors are needed for large scale investigations of arrhythmias associated with SD in horses. We hypothesised that novel wearable devices would provide exercising electrocardiograms (ECGs) of sufficient diagnostic quality for this purpose. Diagnostic quality of ECGs generated by two wearable devices (W2nd™ and Polar Equine™) were compared to simultaneous recordings with a telemetry unit (Televet™) in 5 Thoroughbreds completing 43 separate submaximal exercise tests on a high-speed treadmill. Maximal heart rate (HRmax) generated by mobile applications (HRmaxapp), HRmax after manual correction (HRmaxcorr), percentage of diagnostic ECGs (%diag) at the gallop, and overall quality assessed by visual analogue scale (VAS) were assessed by a blinded observer. HRmaxcorr did not differ significantly between groups. HRmaxapp was significantly lower for W2nd (166.8/min, 95% confidence interval (CI): 160.5-173.1/min) but did not differ significantly between Televet (178.8/min 95% CI: 165.8-191.1/min) and Polar (181.3/min, 95% CI: 174.5-188.1/min). HRmaxcorr was accurate and precise in all runs. HRmaxapp was within a priori limits of agreement in 16/23 W2nd and 18/19 Polar recordings. %diag was significantly lower (77.1%, 95% CI: 67.4-86.8) for W2nd than Polar (100%, 95% CI: 89.9-110.3). VAS was lower for W2nd (46.2, 95% CI: 35.5-57.0) than Polar (90.6, 25% CI: 79.4-101.9). In conclusion, wearable devices appear to be promising tools for investigation of equine exercising arrhythmias in large-scale studies.
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Affiliation(s)
- J. Haughan
- Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA
| | - M. Manriquez
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-447, USA
| | - N.D. Cohen
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, College Station, TX 77843-447, USA
| | - M.A. Robinson
- Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA
- Pennsylvania Equine Toxicology & Research Center, West Chester University, 220 E. Rosedale Ave West Chester, PA 19382, USA
| | - C. Navas de Solis
- Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine, New Bolton Center, 382 West Street Road, Kennett Square, PA 19348, USA
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Evaluation of Cardiac Arrhythmias before, during, and after Treadmill Exercise Testing in Poorly Performing Standardbred Racehorses. Animals (Basel) 2021; 11:ani11082413. [PMID: 34438870 PMCID: PMC8388799 DOI: 10.3390/ani11082413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/06/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022] Open
Abstract
The incidence of significant arrhythmias in sport horses and knowledge about their exact influence on athletic performance need to be clarified. The aims of the present study are to report the prevalence of cardiac arrhythmias during maximal treadmill exercise in poorly performing Standardbreds, and to investigate the possible relationship of demographic, cardiac and performance indices on premature complexes (PCs). Electrocardiographic Holter recordings before, during and after treadmill exercise testing of 158 poorly performing Standardbreds were analyzed retrospectively. Fifty horses did not have any type of arrhythmia. One hundred and eight horses had at least one type of arrhythmia, such as sinus arrhythmia (8.2%), sinoatrial block (3.2%), second-degree atrioventricular block (33.5%), supraventricular PCs (7.6%), and ventricular PCs (48.1%). A multiple regression analysis showed weak evidence that the occurrence of premature complexes decreases as the minimum heart rate increases, and a tendency for these arrhythmias to increase with increasing age and maximum lactate concentration. Our results suggest that PCs are frequent in poorly performing Standardbred racehorses, but further studies are necessary to clarify their role and clinical significance.
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Pedler C, Nath L, Agne GF, Hebart M, Franklin S. Heritability estimates of atrial fibrillation in Thoroughbred racehorses in Hong Kong and Australia. J Vet Cardiol 2021; 36:115-122. [PMID: 34218164 DOI: 10.1016/j.jvc.2021.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Atrial fibrillation (AF) is the most common performance-limiting arrhythmia of racehorses. A genetic contribution has been suggested in Standardbred racehorses but has not been investigated in Thoroughbreds. The objective of this study was to determine the heritability of AF in Thoroughbred racehorses. ANIMALS, MATERIALS AND METHODS Horses racing between 2007 and 2019 in Hong Kong and Australia that had AF detected postrace via auscultation (n = 463 cases) were compared with five randomly selected racing contemporaries (n = 2,315 controls). The ASReml-R programme was used to fit an animal model to the AF data to estimate heritability using the entire data set and a subset of horses (n = 106 cases) that had electrocardiographic confirmation of AF. Variance components were estimated assuming AF was normally distributed and on the logit-transformed scale. The risk of producing AF-affected offspring was calculated using Fisher's exact test for stallions that sired ≥10 individuals in the case-control population. RESULTS Heritability on the underlying scale was 0.064 ± 0.04 (logit animal) and 0.071 ± 0.04 (normal animal) for the entire population and 0.065 ± 0.097 (logit animal) and 0.058 ± 0.11 (normal animal) for electrocardiographic-confirmed AF cases. Of 71 stallions that sired ≥10 individuals, three were more likely to produce affected offspring (odds ratio: 4.05-7.57; p < 0.01). Age (p = 0.991), sex (p = 0.830), and year of birth (p = 0.547) did not contribute to expression. CONCLUSIONS Although some stallions were overrepresented amongst affected horses, the heritability of AF in this population of Thoroughbreds was low. Environmental and individual factors contributing to AF development require further investigation.
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Affiliation(s)
- C Pedler
- School of Animal and Veterinary Science, University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5353, Australia
| | - L Nath
- School of Animal and Veterinary Science, University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5353, Australia
| | - G F Agne
- School of Animal and Veterinary Science, University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5353, Australia
| | - M Hebart
- School of Animal and Veterinary Science, University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5353, Australia
| | - S Franklin
- School of Animal and Veterinary Science, University of Adelaide, Roseworthy Campus, Roseworthy, South Australia, 5353, Australia.
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17
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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; 35:1111-1120. [PMID: 33604980 PMCID: PMC7995445 DOI: 10.1111/jvim.16063] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/25/2021] [Accepted: 02/02/2021] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Atrial fibrillation (AF) impacts performance and horse and jockey safety. Understanding the outcomes of AF identified postrace will better inform regulatory policy. HYPOTHESIS/OBJECTIVES To investigate the outcomes after episodes of AF identified postrace and determine whether affected horses are at increased risk of additional episodes compared to the general racing population. ANIMALS Total of 4684 Thoroughbred racehorses. METHODS Race records for Thoroughbred horses racing in Hong Kong from 2007 to 2017 were reviewed. Horses that performed below expectation were examined by cardiac auscultation and ECG. Incidence and recurrence of AF were compared between horses with and without a history of AF and between horses with paroxysmal and persistent episodes using Fisher's exact test. RESULTS There were 96 135 race starts during the study. Atrial fibrillation was identified in 4.9% of horses, with an overall incidence of 2.7 episodes per 1000 starts. The incidence of AF in horses after any previous episode (12.8 per 1000 starts) was higher than for horses with no previous episode (2.4 per 1000 starts; odds ratio [OR], 5.3; 95% confidence interval [CI], 3.8-7.6). Recurrence was seen in 64% of horses previously treated for persistent AF, which was higher than recurrence in horses with paroxysmal AF (23%; OR, 5.9; 95% CI, 1.6-21.2). Median duration between episodes was 343 days (range, 34-1065). CONCLUSIONS AND CLINICAL IMPORTANCE Thoroughbreds are at increased risk of recurrent AF after both paroxysmal and persistent episodes, but the duration of time between episodes varies widely. These findings support a substantial burden of AF among individual Thoroughbred racehorses.
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Affiliation(s)
- Laura C. Nath
- School of Animal & Veterinary SciencesUniversity of AdelaideRoseworthySouth AustraliaAustralia
| | - Adrian D. Elliott
- Centre for Heart Rhythm Disorders, Adelaide Medical SchoolUniversity of AdelaideAdelaideSouth AustraliaAustralia
| | - Joe Weir
- Hong Kong Jockey Club, Veterinary Clinical ServicesEquine HospitalHong Kong SARHong Kong
| | - Peter Curl
- Veterinary RegulationHong Kong Jockey ClubHong Kong SARHong Kong
| | | | - Samantha Franklin
- School of Animal & Veterinary SciencesUniversity of AdelaideRoseworthySouth AustraliaAustralia
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18
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Rossi TM, Kavsak PA, Maxie MG, Pearl DL, Pyle WG, Physick-Sheard PW. Effect of racing on cardiac troponin I concentration and associations with cardiac rhythm disturbances in Standardbred racehorses. J Vet Cardiol 2021; 35:14-24. [PMID: 33789181 DOI: 10.1016/j.jvc.2021.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 02/01/2021] [Accepted: 02/17/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION/OBJECTIVES Accumulating evidence indicates intense exercise can be associated with myocardial damage. Investigating the impact of maximal effort on myocardium and exploring possible association of injury with rhythm disturbance requires a high-sensitivity cardiac troponin assay. The objectives of this study were: (1) to determine the effect of racing on serum cardiac troponin I (cTnI) in Standardbred horses using a high-sensitivity assay; (2) to determine the 99th percentile of cTnI in healthy horses and investigate the effect of demographic variables on cTnI prevailing pre-race in Standardbred horses using a validated high-sensitivity assay and a contemporary assay, and; (3) to explore associations between exercise-associated arrhythmia and cTnI concentration. ANIMALS Racehorses (n = 145). MATERIALS AND METHODS ≤ 2 h pre-race, cTnI concentrations were measured in 158 race starts. Electrocardiogram (ECG) monitoring was applied during racing and race recovery and screened for complex ventricular arrhythmia. Associations between cTnI prevailing before racing concentration, age, sex, and gait were investigated. Demographic and performance variables were evaluated for associations with cTnI concentration post-race and rhythm disturbance. RESULTS Incidence of arrhythmia was 11.6% (16 horses). A significant increase in median (interquartile range) cTnI concentration of 1.36 (0.49-2.81) ng/L was found post-race (p < 0.0001). Serum cardiac troponin I (cTnI) concentration prevailing pre-race was positively associated with increasing age, and gait. Serum cardiac troponin I prevailing post-race was positively associated with concentration prevailing pre-race. Interaction between arrhythmia and finishing distanced revealed horses finishing distanced and experiencing arrhythmia displayed higher cTnI release than with the presence of either alone. CONCLUSIONS Racing increased cTnI concentration. Horses finishing distanced and also exhibiting arrhythmia may be experiencing myocardial compromise.
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Affiliation(s)
- T M Rossi
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Ontario, N1G 2W1, Canada.
| | - P A Kavsak
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main Street West, HSC-2N16, Hamilton, ON, L8S 4K1, Canada
| | - M G Maxie
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, Laboratory Services Division, Building 89, 419 Gordon St., Ontario, N1G 2W1, Canada
| | - D L Pearl
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Ontario, N1G 2W1, Canada
| | - W G Pyle
- Centre for Cardiovascular Research, Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Ontario, N1G 2W1, Canada
| | - P W Physick-Sheard
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, 50 Stone Rd E, Ontario, N1G 2W1, Canada
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19
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Prevalence of cardiac arrhythmias and R-R interval variation in healthy Thoroughbred horses during official Chuckwagon races and recovery. Vet J 2020; 267:105583. [PMID: 33375959 DOI: 10.1016/j.tvjl.2020.105583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 11/12/2020] [Accepted: 11/16/2020] [Indexed: 11/22/2022]
Abstract
The prevalence and severity of cardiac arrhythmias in healthy racehorses undergoing competition is not well defined. The aim was to characterize arrhythmias in Thoroughbreds participating in official Chuckwagon races and to determine normal beat-to-beat (R-R) variability during supramaximal exercise. Electrocardiograph (ECG) recordings were obtained during pre-race, race, and active-recovery from 82 clinically healthy Thoroughbreds. ECG recordings were analyzed for arrhythmias and mean percent R-R deviation. Plasma lactate and high-sensitivity troponin (hs-cTnT) were also measured. Fifty-two ECGs were included in the analysis. Arrhythmias were seen in 48/52 horses (92%) and were predominantly isolated events. No complex rhythms were observed. During the race, 92% of horses had arrhythmias (81% supraventricular premature complex [SVPC]; 33% ventricular premature complex [VPC]). Eleven percent of racing arrhythmias were VPCs (all singlets except for two couplets). During active-recovery, 58% of horses had arrhythmias (56% SVPC; 15% VPCs): Three horses had VPC couplets and one horse had a VPC triplet. All plasma hs-cTnT were within normal limits. The measured lactate was 28.5 ± 4.5 mmol/L, confirming supramaximal exercise. R-R variation ranged between -9.5 to +18.8% during pre-race (mean heart rate [HR], 155 ± 22 beats per min [bpm]), -27.8 to +45.3% during racing (mean HR, 200 ± 9 bpm) and -16.4 to +40.1% during active-recovery (mean HR, 165 ± 14 bpm). Maximal and 1st percentile R-R shortening and lengthening were significantly greater at race than pre-race and active-recovery (P < 0.0001). Racing and active-recovery maximal R-R lengthening were significantly greater than pre-race (P = 0.0003). Supraventricular premature complexes and VPCs are prevalent in healthy horses undergoing Chuckwagon racing. R-R variation is greater during racing than has previously been described.
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Slack J, Stefanovski D, Madsen TF, Fjordbakk CT, Strand E, Fintl C. Cardiac arrhythmias in poorly performing Standardbred and Norwegian-Swedish Coldblooded trotters undergoing high-speed treadmill testing. Vet J 2020; 267:105574. [PMID: 33375960 DOI: 10.1016/j.tvjl.2020.105574] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 10/22/2020] [Accepted: 10/30/2020] [Indexed: 11/28/2022]
Abstract
The significance of cardiac arrhythmias and their possible association with upper airway obstruction are frequently considered in the clinical investigation of poor performance. The specific aims of this retrospective study of a group of poorly performing Standardbred and Norwegian-Swedish Coldblooded trotters were to: (1) describe the overall frequency and frequency distributions of arrhythmias; (2) describe arrhythmia characteristics including percent prematurity, relative recovery cycle lengths and QRS morphology; (3) describe variability of normal RR intervals; and (4) explore possible associations between upper airway abnormalities and arrhythmia categories during peak exercise and recovery. The records of 103 trotters presented to the Norwegian University of Life Sciences for high-speed treadmill testing were reviewed. The occurrence of at least one arrhythmic event was high (77-78%) when considering all exercise periods and 6-10% prematurity criteria. Triplets, salvos, and/or paroxysmal tachyarrhythmias occurred in 8% of horses during peak exercise. Complex ventricular arrhythmias occurred in 15% of horses in the first 2 min of recovery. Evaluation of QRS morphology and return cycle lengths demonstrated areas of overlap in characteristics typically attributed to either supraventricular or ventricular arrhythmias. There was no association between airway diagnosis and arrhythmias during any exercise period. The maximum average HR during peak exercise was an excellent predicter for complex ventricular arrhythmias during recovery. Because perfect categorization of arrhythmias is not possible, future studies should report descriptive arrhythmia information. Prospective studies that evaluate various degrees of upper airway obstruction and the effect on known initiators of arrhythmogenesis are needed.
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Affiliation(s)
- J Slack
- University of Pennsylvania, New Bolton Center, Department of Clinical Studies, 382 West Street Rd Kennett Square, PA 19348, USA.
| | - D Stefanovski
- University of Pennsylvania, New Bolton Center, Department of Clinical Studies, 382 West Street Rd Kennett Square, PA 19348, USA
| | - T F Madsen
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Department of Companion Animal Clinical Sciences, P.O. Box 369 Sentrum, N-0102 Oslo, Norway
| | - C T Fjordbakk
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Department of Companion Animal Clinical Sciences, P.O. Box 369 Sentrum, N-0102 Oslo, Norway
| | - E Strand
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Department of Companion Animal Clinical Sciences, P.O. Box 369 Sentrum, N-0102 Oslo, Norway
| | - C Fintl
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Department of Companion Animal Clinical Sciences, P.O. Box 369 Sentrum, N-0102 Oslo, Norway
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Reef VB, Davidson EJ, Slack J, Stefanovski D. Hypercapnia and hyperlactatemia were positively associated with higher-grade arrhythmias during peak exercise in horses during poor performance evaluation on a high-speed treadmill. Vet J 2020; 266:105572. [PMID: 33323171 DOI: 10.1016/j.tvjl.2020.105572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 10/09/2020] [Accepted: 11/02/2020] [Indexed: 01/21/2023]
Abstract
Cardiac arrhythmias are common in horses during exercise, especially immediately post-exercise. The objectives of this study were to: (1) describe the frequency and type of cardiac arrhythmias detected in horses during incremental high-speed treadmill exercise testing (ITET); (2) determine if arterial blood gas (ABG) changes at peak and immediately post-exercise were associated with arrhythmias; and (3) determine whether upper or lower airway disease was associated with exercising cardiac arrhythmias. Horses (n = 368) presenting for an ITET underwent resting and exercising upper airway endoscopy, resting, exercising and post-exercise electrocardiography, resting and post-exercise echocardiography and exercising ABG. Arrhythmias were graded by the most severe arrhythmia present. Grade 1 arrhythmias were defined as one or two atrial (APCs) or ventricular premature complexes (VPCs), or one APC and one VPC, detected in 6.9% at peak and 16% at 0-2 min post exercise.. Grade 2 arrhythmias were >2 APCs or VPCs, or both, detected in 5.8% at peak and 16.6% at 0-2 min post exercise. Grade 3 included complex arrhythmias (couplets, triplets, R on T, multiform complexes or paroxysmal atrial or ventricular tachycardia), detected in 4.4% at peak and 7.3% at 0-2 min post exercise. Both partial pressure of arterial CO2 (PaCO2; P = 0.008) and lactate (P = 0.031) were significantly associated with arrhythmias occurring at peak exercise, but not immediately post-exercise. As PaCO2 and lactate increased, arrhythmia severity increased. Blood pH was significantly associated with grades 2 and 3 arrhythmias at 0-2 min post ITET (OR = 0.0002; P < 0.001). There was no significant association between grades 2 and 3 cardiac arrhythmias, inflammatory airway disease (IAD), or exercise-induced pulmonary hemorrhage (EIPH). When adjusted for lactate concentration (P = 0.06), higher PaCO2 concentrations in horses with and without exercising upper respiratory tract (URT) obstruction were associated with higher likelihood of grades 2 and 3 arrhythmias (P < 0.01). This study demonstrated that at peak exercise, with severe hypercapnia and hyperlactatemia, there was increased risk for grades 2 or 3 cardiac arrhythmias and, as the PaCO2 and lactate values increased further, the severity of those arrhythmias increased.
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Affiliation(s)
- V B Reef
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, 382 West Street Rd., Kennett Square, PA 19348, USA.
| | - E J Davidson
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, 382 West Street Rd., Kennett Square, PA 19348, USA
| | - J Slack
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, 382 West Street Rd., Kennett Square, PA 19348, USA
| | - D Stefanovski
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, 382 West Street Rd., Kennett Square, PA 19348, USA
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22
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Marr CM, Franklin S, Garrod G, Wylie C, Smith L, Dukes-McEwan J, Bright J, Allen K. Exercise-associated rhythm disturbances in poorly performing Thoroughbreds: risk factors and association with racing performance. Equine Vet J 2020; 53:656-669. [PMID: 32979227 DOI: 10.1111/evj.13354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 07/09/2020] [Accepted: 09/01/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Exercise-associated cardiac rhythm disturbances are common, but there is a lack of evidence-based criteria on which to distinguish clinically relevant rhythm disturbances from those that are not. OBJECTIVES To describe and characterise rhythm disturbances during clinical exercise testing; to explore potential risk factors for these rhythm disturbances and to determine whether they influenced future racing. STUDY DESIGN Retrospective cohort using a convenience sample. METHODS Medical records were reviewed from two clinical services to identify horses with poor performance and/or respiratory noise with both exercise endoscopy and electrocardiography results. Respiratory and ECG findings recorded by the attending clinicians were described, and for polymorphic ventricular rhythms (n = 12), a consensus team agreed the final rhythm characterisation. Several statistical models analysing risk factors were built and racing records were reviewed to compare horses with and without rhythm disturbance. RESULTS Of 245 racehorses, 87 (35.5%) had no ectopic/re-entrant rhythms, 110 (44.9%) had isolated premature depolarisations during sinus rhythm and 48 (19.6%) horses had complex tachydysrrythmias. Rhythm disturbances were detected during warm-up in 20 horses (8.2%); during gallop in 61 horses (24.9%) and during recovery in 124 horses (50.6%). Most complex rhythm events occurred during recovery, but there was one horse with a single couplet during gallop and another with a triplet during gallop. Fifteen horses (one with frequent isolated premature depolarisations and 14 complex rhythms) were considered by clinicians to be potentially contributing to poor performance. Treadmill exercise tests, the presence of exercise-associated upper respiratory tract obstructions and National Hunt racehorses were associated with rhythm disturbances. The proportion of horses racing again after diagnosis (82%) was similar in all groups and univariable analysis revealed no significant associations between subsequent racing and the presence of any ectopic/re-entrant rhythm, or the various sub-groups based on phase of exercise in which this was detected. MAIN LIMITATIONS Reliance on retrospective data collection from medical records with no control group. Exercise ECGs were collected using only 1 or 2 leads. Variables examined as risk factors could be considered to be inter-related and our sub-groups were small. CONCLUSIONS This study confirms a high prevalence of cardiac rhythm disturbances, including complex ectopic/re-entrant rhythms, in poorly performing racehorses. Detection of rhythm disturbances may vary with exercise test conditions and exercise-associated upper respiratory tract obstructions increase the risk of rhythm disturbances.
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Affiliation(s)
| | - Samantha Franklin
- Equine Sports Medicine Centre, Bristol Vet School, University of Bristol, Bristol, UK.,Equine Health and Performance Centre, University of Adelaide, South Australia, SA, Australia
| | | | | | | | - Jo Dukes-McEwan
- Department of Small Animal Clinical Science (Cardiology Service), Institute of Veterinary Science, Leahurst Campus, University of Liverpool, Neston, Cheshire, UK
| | - Jan Bright
- Colorado State University Veterinary Teaching Hospital, Fort Collins, CO, USA
| | - Kate Allen
- Equine Sports Medicine Centre, Bristol Vet School, University of Bristol, Bristol, UK
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23
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Affiliation(s)
| | - Joann Slack
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, USA
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24
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Yu Q, Wang J, Dai M, Zhang Y, Cao Q, Luo Q, Shu L, Bao M. Night-Time Premature Ventricular Complex Positively Correlates With Cardiac Sympathetic Activity in Patients Undergoing Radiofrequency Catheter Ablation. Heart Lung Circ 2020; 29:1152-1163. [DOI: 10.1016/j.hlc.2019.11.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/15/2019] [Accepted: 11/17/2019] [Indexed: 10/25/2022]
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25
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Abstract
There have been some advances in understanding the genetic contribution to ventricular septal defects in Arabians, sudden death in racehorses, and atrial fibrillation in racehorses. No genetic analyses have been published for aortic rupture in Friesians or atrioventricular block in donkeys despite strong evidence for a genetic cause. To date, no genetic mutation has been identified for any equid cardiac disease. With the advancement of genetic tools and resources, we are moving closer to discoveries that may explain the heritable basis of inherited equid cardiac disease.
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Affiliation(s)
- Samantha L Fousse
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA; Stern Comparative Cardiac Genetics Laboratory, UC Davis, 2108 Tupper Hall, One Shields Avenue, Davis, CA 95616, USA
| | - Joshua A Stern
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, USA; Stern Comparative Cardiac Genetics Laboratory, UC Davis, 2108 Tupper Hall, One Shields Avenue, Davis, CA 95616, USA.
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26
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Navas de Solis C. Ventricular arrhythmias in horses: Diagnosis, prognosis and treatment. Vet J 2020; 261:105476. [PMID: 32741491 DOI: 10.1016/j.tvjl.2020.105476] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 05/26/2020] [Accepted: 05/26/2020] [Indexed: 01/02/2023]
Abstract
Ventricular arrhythmias (VAs) are often incidental or coincidental with systemic disease. Ventricular arrhythmias are also the most likely cause of many sudden cardiac deaths in horses. This dichotomy creates challenges in the management of horses with VAs. This review presents current knowledge of diagnosis, prognosis and treatment of VAs in horses.
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Affiliation(s)
- Cristobal Navas de Solis
- Department of Clinical Studies New Bolton Center, University of Pennsylvania, Kennett Square, PA 19348, USA.
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27
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Van Steenkiste G, van Loon G, Crevecoeur G. Transfer Learning in ECG Classification from Human to Horse Using a Novel Parallel Neural Network Architecture. Sci Rep 2020; 10:186. [PMID: 31932667 PMCID: PMC6957496 DOI: 10.1038/s41598-019-57025-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 12/20/2019] [Indexed: 11/09/2022] Open
Abstract
Automatic or semi-automatic analysis of the equine electrocardiogram (eECG) is currently not possible because human or small animal ECG analysis software is unreliable due to a different ECG morphology in horses resulting from a different cardiac innervation. Both filtering, beat detection to classification for eECGs are currently poorly or not described in the literature. There are also no public databases available for eECGs as is the case for human ECGs. In this paper we propose the use of wavelet transforms for both filtering and QRS detection in eECGs. In addition, we propose a novel robust deep neural network using a parallel convolutional neural network architecture for ECG beat classification. The network was trained and tested using both the MIT-BIH arrhythmia and an own made eECG dataset with 26.440 beats on 4 classes: normal, premature ventricular contraction, premature atrial contraction and noise. The network was optimized using a genetic algorithm and an accuracy of 97.7% and 92.6% was achieved for the MIT-BIH and eECG database respectively. Afterwards, transfer learning from the MIT-BIH dataset to the eECG database was applied after which the average accuracy, recall, positive predictive value and F1 score of the network increased with an accuracy of 97.1%.
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Affiliation(s)
- Glenn Van Steenkiste
- Department of large animal internal medicine, Ghent University, Ghent, 9000, Belgium.
| | - Gunther van Loon
- Department of large animal internal medicine, Ghent University, Ghent, 9000, Belgium
| | - Guillaume Crevecoeur
- Department of Electromechanical, System and Metal Engineering, Ghent University, Ghent, 9000, Belgium.,Core Lab EEDT-DC, Flanders Make, Belgium
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28
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Gallant L, Jacob S, Tadros E, Woodrow J, Hines M, Ewart S, Schott H. Rapid screening for cardiac arrhythmias in competition draft horses. COMPARATIVE EXERCISE PHYSIOLOGY 2019. [DOI: 10.3920/cep190029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cardiac arrhythmias may cause decreased performance and sudden death during exercise. Our objectives were: (1) to determine prevalence of unrecognised arrhythmias in a population of competition draft horses by performing short duration screening electrocardiograms (ECGs) at rest; and (2) to assess utility of a commercial handheld device for recording equine ECGs. Owners or trainers of 244 draft horses (age 0.5-16 years), including 82 Percherons, 69 Belgians, 69 Clydesdales, 11 Belgian mules, 8 Shires, and 5 Percheron mules, were queried to determine signalment, performance history, and known arrhythmias. All horses were auscultated for 30 s and ECGs were obtained in 204 horses using a handheld recording device (AliveCor®). ECGs were reviewed for quality and used to determine heart rate (HR) and rhythm. When ECG tracing quality permitted, PQ and QT intervals were also measured. ECGs displaying RR intervals adequate for HR determination and rhythm assessment were recorded from 161 horses (79%) while tracings with consistent P waves, QRS complexes, and T waves were recorded from only 47 horses (23%). Four arrhythmias were detected by both auscultation and ECG: atrial fibrillation (1), premature complexes (1), and second-degree atrioventricular block (2). None of these horses had a history of poor performance or previous recognition of an arrhythmia. The prevalence of unrecognised, and potentially clinically significant, arrhythmias in draft horses at rest appears to be low (2/244; 0.8%, 95% confidence interval 0.1-2.9%). Longer recordings at rest, as well as recordings during and immediately after exercise, would likely have revealed a higher prevalence of arrhythmias.
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Affiliation(s)
- L.R. Gallant
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd Room D202, East Lansing, MI 48824, USA
- Newcastle Equine Centre, P.O. Box 123, Broadmeadow, New South Wales 2292, Australia
| | - S.I. Jacob
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd Room D202, East Lansing, MI 48824, USA
| | - E.M. Tadros
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd Room D202, East Lansing, MI 48824, USA
| | - J.S. Woodrow
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, 2407 River Dr, Knoxville, TN 37996, USA
| | - M.T. Hines
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, 2407 River Dr, Knoxville, TN 37996, USA
| | - S.L. Ewart
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd Room D202, East Lansing, MI 48824, USA
| | - H.C. Schott
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Rd Room D202, East Lansing, MI 48824, USA
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Vezzosi T, Vitale V, Sgorbini M, Tognetti R, Bonelli F. Two Methods for 24-hour Holter Monitoring in Horses: Evaluation of Recording Performance at Rest and During Exercise. J Equine Vet Sci 2019; 79:127-130. [PMID: 31405491 DOI: 10.1016/j.jevs.2019.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 11/27/2022]
Abstract
Continuous electrocardiography (ECG) monitoring is the gold standard for diagnosing arrhythmias that occur intermittently or under exercise. The aim of this study was to compare two different methods for 24-hour Holter monitoring in horses, a 7-electrode system (7-ES) versus a 4-electrode system (4-ES), assessing the recording performance at rest and during exercise. Six standardbred horses were included in the present prospective study. Two different methods for 24-hour Holter monitoring were used in each horse with a washout period of one week between each recording method. In the first 15 minutes of the 24-hour Holter monitoring, a standard exercise test was performed. Holter recordings were analyzed in terms of the number of recorded hours; the number of detached electrodes (DEs); and total duration of artifacts over the 15-minute exercise. The number of recorded hours was significantly higher in the 7-ES (24 hours, range: 23-24 hours) than the 4-ES (6.5 hours, range: 1.2-20 hours; P < .05). The number of DEs was not significantly different between the two systems. The total duration of artifacts over the 15-minute exercise was significantly higher in the 7-ES (155 seconds, range: 35-378 seconds) than in the 4-ES (25 seconds, range: 10-32 seconds; P < .05). Our results showed a better recording performance during exercise using the 4-ES because of the lower number of artifacts. The 7-ES showed a better performance in terms of recording duration. In conclusion, we suggest using the 4-ES for exercise tests and the 7-ES when a longer ECG recording at rest is required.
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Affiliation(s)
- Tommaso Vezzosi
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Valentina Vitale
- Sydney School of Veterinary Science, The University of Sydney, Camden, NSW, Australia
| | - Micaela Sgorbini
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy
| | - Rosalba Tognetti
- Department of Veterinary Sciences, University of Pisa, Pisa, Italy.
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30
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Molesan A, Wang M, Sun Q, Pierce V, Desideri R, Palmer S, Todhunter R, Kelly K. Cardiac Pathology and Genomics of Sudden Death in Racehorses From New York and Maryland Racetracks. Vet Pathol 2019; 56:576-585. [PMID: 30917748 DOI: 10.1177/0300985819829529] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Postmortem evaluation of racehorses has focused primarily on musculoskeletal injuries; however, horses also die suddenly on the track (sudden death [SD]). Although cardiac conditions are frequently suspected as a cause of death, SD racehorses are often autopsy negative; however, previous studies have been limited due to inconsistent or insufficient cardiac sampling and lack of controls. SD in New York (NY) and Maryland (MD) racehorses was evaluated in an observational case vs control study comparing clinical information, postmortem evaluation including cardiac dissection, and cardiac conduction system histopathology. In the study period, there were 40 cases of SD. In NY, SD occurred in 12% (37/316) of submissions, and 36 (11%) cases of SD were exercise associated (EASD); 3 EASD cases occurred in MD. In NY/MD EASD cases with histologic examination of the heart, 11 of 36 (31%) had significant lesions, including mesenteric artery rupture (1), axial trauma (2), systemic inflammation (2), pulmonary hemorrhage (1), and cardiac disease (5). Mild myocardial fibrosis, mild inflammation, coronary arteriosclerosis, and variation in cardiac nodal connective tissue were present in both SD cases and controls and thus were not considered to be causes of SD. While not excluding a genetic basis for SD, analysis of the genotypes (GGP Equine 70 K Array) of cases and controls did not reveal significant differences in allele frequencies at any locus. Most SD racehorses were autopsy negative; further research using standardized protocols and controls is needed to understand the underlying causes of SD, which is crucial to protecting the viability of racing.
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Affiliation(s)
- Alex Molesan
- 1 Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Minghui Wang
- 2 Computational Biology Service Unit, Cornell University, Ithaca, NY, USA
| | - Qi Sun
- 2 Computational Biology Service Unit, Cornell University, Ithaca, NY, USA
| | - Virginia Pierce
- 3 College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Rhiannon Desideri
- 1 Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Scott Palmer
- 4 Departments of Biomedical Sciences and Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA.,5 New York State Gaming Commission, Schenectady, NY, USA
| | - Rory Todhunter
- 6 Deptartment of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Kathleen Kelly
- 1 Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
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31
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Durando MM. Cardiovascular Causes of Poor Performance and Exercise Intolerance and Assessment of Safety in the Equine Athlete. Vet Clin North Am Equine Pract 2019; 35:175-190. [PMID: 30871825 DOI: 10.1016/j.cveq.2018.12.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Horses have a high prevalence of resting arrhythmias, cardiac murmurs, and valvular regurgitation, and training can increase the prevalence. This makes it challenging for equine veterinarians who are asked to evaluate horses for poor performance to determine the clinical relevance of some findings. In addition, cardiac disease has the potential to cause collapse or sudden death, putting both the horse and rider at risk. Further diagnostics, such as echocardiograms and resting and exercising ECGs can help to sort out the impact of an abnormality found on resting physical examination. However uncertainty over the importance of some findings continues to exist.
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Affiliation(s)
- Mary M Durando
- Equine Sports Medicine Consultants, LLC, 40 East Main Street, Suite 232, Newark, DE 19711, USA.
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32
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Navas de Solis C. Cardiovascular Response to Exercise and Training, Exercise Testing in Horses. Vet Clin North Am Equine Pract 2019; 35:159-173. [PMID: 30871829 DOI: 10.1016/j.cveq.2018.11.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The physiology of exercise and training is fascinating, and hundreds of interesting studies have given insight into its mechanisms. Exercise testing is a useful clinical tool that can help veterinarians assess poor performance, fitness, and performance potential and prevent injuries. The clinically applicable aspects of cardiovascular adaptions to training and exercise testing are highlighted in this review. Different exercise tests should be used to evaluate horses performing in different disciplines and levels. Exercise tests that simultaneously assess several body systems can be beneficial when assessing poor performance, because this is often a multifactorial problem with signs not detectable at rest.
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Affiliation(s)
- Cristobal Navas de Solis
- Department of Large Animal Clinical Sciences, Texas A&M University, 4475 TAMU, College Station, TX 77843-4475, USA.
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33
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Lorello O, Ramseyer A, Burger D, Gerber V, Navas de Solis C. Cardiovascular variables in eventing and endurance horses over a season. J Vet Cardiol 2019; 21:67-78. [DOI: 10.1016/j.jvc.2018.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 08/19/2018] [Accepted: 08/20/2018] [Indexed: 10/27/2022]
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34
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Frick L, Schwarzwald CC, Mitchell KJ. The use of heart rate variability analysis to detect arrhythmias in horses undergoing a standard treadmill exercise test. J Vet Intern Med 2018; 33:212-224. [PMID: 30520119 PMCID: PMC6335521 DOI: 10.1111/jvim.15358] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/08/2018] [Indexed: 12/03/2022] Open
Abstract
Background Little is known about normal heart rate variability (HRV) in horses during exercise. It can be difficult to separate premature beats from normal beat‐to‐beat variation at higher heart rates. Objectives The aim was to quantify HRV in healthy horses during a high‐speed treadmill‐standardized exercise test (HSET) and to compare with the HRV in horses observed to have arrhythmias during exercise. Animals Thirteen healthy horses (Group H), 30 horses with arrhythmias (Group A), and 11 horses with poor performance but no observed arrhythmias (Group O). Methods Prospective, observational study. All horses performed a HSET with simultaneous electrocardiograph (ECG) recorded. The ECGs were corrected for artifacts, and arrhythmias noted. Percent instantaneous beat‐to‐beat cycle length variation (% R‐R variation) was calculated, and HRV analyses were performed on trot, canter, and recovery segments. Results Group H showed between −4.4 and +3.8% R‐R variation during trot and between −6.1 and +5.4% R‐R variation during the canter phase of the HSET. Group A had significantly larger maximum and 1st percentile R‐R shortening and lengthening compared with Group H and Group O during the recovery phase where most arrhythmias were observed. During recovery, a cutoff of 6% maximum % R‐R shortening predicted the presence of arrhythmia with 88% sensitivity and 97% specificity and likelihood ratio of 26. Conclusions and Clinical Importance Healthy horses have little instantaneous R‐R variation during exercise. If a cardiac cycle shortens more than 6% from the previous cycle during the recovery phase, this R‐R interval is likely to represent an arrhythmic event.
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Affiliation(s)
- Ladina Frick
- Equine Department, Clinic for Equine Internal Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Colin C Schwarzwald
- Equine Department, Clinic for Equine Internal Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Katharyn J Mitchell
- Equine Department, Clinic for Equine Internal Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Abstract
Cardiac murmurs are not uncommonly detected in the equine athlete. Although most are benign in nature, differentiation and quantification of murmurs due to valvular regurgitation are important for prognosis and recommendations. Arrhythmias can be associated with structural disease or occur independently and may range in severity from minimal clinical effect to poor performance to presenting a safety risk to rider and horse. This article discusses commonly encountered cardiac conditions in the sport horse. Physical examination, diagnostic approach, valvular disease, and arrhythmias with an impact on performance or ridden safety are discussed.
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Affiliation(s)
- Katherine B Chope
- Department of Clinical Sciences, Tufts University Cummings School of Veterinary Medicine, 200 Westboro Road, North Grafton, MA 01536, USA.
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36
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Rossi TM, Kavsak PA, Maxie MG, Pearl DL, Pyle WG, Physick-Sheard PW. Post-exercise cardiac troponin I release and clearance in normal Standardbred racehorses. Equine Vet J 2018. [DOI: 10.1111/evj.12967] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- T. M. Rossi
- Department of Population Medicine; Ontario Veterinary College; University of Guelph; Guelph Ontario Canada
| | - P. A. Kavsak
- Department of Pathology and Molecular Medicine; McMaster University; Hamilton Ontario Canada
| | - M. G. Maxie
- Animal Health Laboratory; Laboratory Services Division; University of Guelph; Guelph Ontario Canada
| | - D. L. Pearl
- Department of Population Medicine; Ontario Veterinary College; University of Guelph; Guelph Ontario Canada
| | - W. G. Pyle
- Centre for Cardiovascular Research; Department of Biomedical Sciences; Ontario Veterinary College; University of Guelph; Guelph Ontario Canada
| | - P. W. Physick-Sheard
- Department of Population Medicine; Ontario Veterinary College; University of Guelph; Guelph Ontario Canada
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37
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Physick-Sheard PW, Avison A, Chappell E, MacIver M. Ontario Racehorse Death Registry, 2003-2015: Descriptive analysis and rates of mortality. Equine Vet J 2018; 51:64-76. [PMID: 29672910 DOI: 10.1111/evj.12955] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 03/31/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND The Province of Ontario maintains a registry of racehorse deaths occurring within 60 days of a race or trial entry that provides insight into mortality rates and costs of competition. OBJECTIVES To characterise and quantify mortality and identify breed differences. STUDY DESIGN Retrospective annualised cohort study. METHODS The Ontario Death Registry for 2003-2015, containing 1713 cases, was audited and information on the relationship between death and official work added. Race and trial data from industry performance databases were used to determine mortality rates according to breed, year, age, sex and circumstances of death. RESULTS Breed differences in mortality rate and individual risk were found. Thoroughbreds (Tb) had the greatest exercise-associated mortality (EAM) rate and risk by all measures (2.27 deaths/1000 race starts, 0.95-1.0% annual individual risk), followed by Quarter horses (Qh, 1.49, 0.60-0.69%). Rate and risk were lowest for Standardbreds (Sb, 0.28, 0.23-0.24%). Nonexercise annual individual risk was highest for the Sb (0.45%, vs. Tb 0.33%, and Qh 0.32%). Pattern and type of EAM mirrored the characteristics of competitive activity in each industry, with high Tb and Qh mortality being associated with exercise and involving musculoskeletal injuries, dying suddenly and accidents. Low Sb EAM reflected the more extensive nature of training preparation and racing for this breed. MAIN LIMITATIONS Available data provided no information on morbidity, mortality beyond the 60-day horizon or for horses not racing. Numbers for the Qh were low. CONCLUSIONS Race-intensity exercise is clearly hazardous for horses, with hazards varying widely between breeds and showing parallels with industry cultural and management norms. Breed differences provide insights concerning strategies that could reduce mortality, while improving welfare and reducing costs of participation. For all breeds, musculoskeletal injury was the major contributing cause of mortality.
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Affiliation(s)
- P W Physick-Sheard
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada
| | - A Avison
- DVM Program, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - E Chappell
- DVM Program, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - M MacIver
- DVM Program, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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Kraus M, Physick-Sheard P, Brito LF, Sargolzaei M, Schenkel FS. Marginal ancestral contributions to atrial fibrillation in the Standardbred racehorse: Comparison of cases and controls. PLoS One 2018; 13:e0197137. [PMID: 29763439 PMCID: PMC5953485 DOI: 10.1371/journal.pone.0197137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 04/26/2018] [Indexed: 11/30/2022] Open
Abstract
Admissions of Standardbred racehorses (Std) to the Ontario Veterinary College Teaching Hospital (OVCTH) for treatment of atrial fibrillation (AF) began to increase in the early 1990s. The arrhythmia has been shown to have a modest heritability (h2 ≃ 0.15), with some stallions appearing as sires or sires of mares used in breeding (broodmares) of affected horses more frequently than others. The objective of this study was to determine the marginal genetic contributions of ancestors to cohorts of Std affected with AF and their contemporary control groups, and whether these ancestors contribute significantly more to the affected cohorts than to controls. All Std admitted to OVCTH for treatment of AF that were born between 1993 and 2007 comprised the affected case group (n = 168). Five randomly selected racing contemporaries for each Std admitted, assumed to not suffer from the arrhythmia, comprised the control group (n = 840). Three-year overlapping cohorts were created for case and control horses, determined according to year of birth, for a total of 26 cohorts. Marginal genetic contributions of ancestors to each cohort were determined and differences analyzed for statistical significance using a two-tailed paired t-test, with P ≤ 0.05 considered significant. The marginal contributions of 26 ancestors were significant, with 11 contributing significantly more to affected cohorts than the corresponding controls, and 15 contributing significantly more to controls than the corresponding affected cohorts. One stallion and one broodmare were very highly significant to affected cohorts at P ≤ 0.001, and nine stallions and three broodmares were very highly significant to control cohorts at P ≤ 0.001. Therefore, a number of stallions have statistically significant contributions to the genetics of Std affected with AF, while many others have statistically significant contributions to healthy Std. The arrhythmia appears to be particularly prevalent in the descendants of one sire family.
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Affiliation(s)
- Megan Kraus
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
| | - Peter Physick-Sheard
- Department of Population Medicine, University of Guelph, Guelph, Ontario, Canada
| | - Luiz F. Brito
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
| | - Mehdi Sargolzaei
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
- The Semex Alliance, Guelph, Ontario, Canada
| | - Flávio S. Schenkel
- Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada
- * E-mail:
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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; 32:1410-1419. [PMID: 29749082 PMCID: PMC6060327 DOI: 10.1111/jvim.15137] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 03/14/2018] [Accepted: 03/27/2018] [Indexed: 11/29/2022] Open
Abstract
Background Atrial fibrillation (AF) is the most common arrhythmia affecting performance in horses. However, no previous studies have quantified the performance reduction in horses suffering from AF. Objectives To quantify the effect of AF on maximum velocity (Vmax), maximum heart rate (HRmax), heart rate recovery (T100), hematologic parameters and development of abnormal QRS complexes. Animals Nine Standardbred trotters. Methods Two‐arm controlled trial. Six horses had AF induced by means of a pacemaker and 3 served as sham‐operated controls. All horses were subjected to an exercise test to fatigue before (SET1) and after (SET2) 2 months of AF or sham. The Vmax and HRmax were assessed using a linear mixed normal model. Abnormal QRS complexes were counted manually on surface ECGs. Results Atrial fibrillation resulted in a 1.56 m/sec decrease in Vmax (P < .0001). In the AF group, HRmax ± SD increased from 226 ± 11 bpm at SET1 to 311 ± 27 bpm at SET 2. The AF group had higher HRmax at SET2 compared with controls (P < .0001), whereas no difference between the control and AF groups was observed at SET1 (P = .96). Several episodes of wide complex tachycardia were observed during exercise in 3 of the AF horses during SET2. Conclusions and Clinical Importance Atrial fibrillation resulted in a significant reduction in performance, an increase in HR and development of abnormal QRS complexes during exercise, which may be a risk factor for collapse or sudden cardiac death.
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Affiliation(s)
- Rikke Buhl
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Eva Zander Hesselkilde
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Bjørg Zinkernagel Klein
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Karen Margrethe Hougaard
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Kirsten Bomberg Ravn
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | | | - Merle Friederike Fenner
- Department of Veterinary Clinical Sciences, University of Copenhagen, Taastrup, Copenhagen, Denmark
| | - Christian Pipper
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Jespersen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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40
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Gunther-Harrington CT, Arthur R, Estell K, Martinez Lopez B, Sinnott A, Ontiveros E, Varga A, Stern JA. Prospective pre- and post-race evaluation of biochemical, electrophysiologic, and echocardiographic indices in 30 racing thoroughbred horses that received furosemide. BMC Vet Res 2018; 14:18. [PMID: 29347921 PMCID: PMC5774161 DOI: 10.1186/s12917-018-1336-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/04/2018] [Indexed: 11/23/2022] Open
Abstract
Background Exercise induced cardiac fatigue (EICF) and cardiac dysrhythmias are well described conditions identified in high-level human athletes that increase in frequency with intensity and duration of exercise. Identification of these conditions requires an understanding of normal pre- and post-race cardiac assessment values. The objectives of this study were to (1) characterize selected indices of cardiac function, electrophysiologic parameters, and biochemical markers of heart dysfunction prior to and immediately after high level racing in Thoroughbred horses receiving furosemide; and (2) create pre- and post-race reference values in order to make recommendations on possible screening practices for this population in the future. Results Thirty Thoroughbred horses were enrolled in the study with an age range of 3–6 years. All horses received furosemide prior to racing. Physical exams, ECGs, and echocardiograms were performed prior to racing (T0) and within 30–60 min following the race (T1). Blood samples were obtained at T0, T1, 4 h post-race (T4) and 24 h after the race (T24). Electrolytes, hematocrit, cardiac troponin I, and partial pressure CO2 values were obtained at all time points. Heart rate was significantly increased post-race compared to baseline value with a median difference of 49 bpm, 95% CI [31,58],(P < 0.0001). No dysrhythmias were noted during ECG assessment. Following the race, an increase in number of horses demonstrating regurgitation through the aorta and AV valves was noted. Systolic function measured by fractional shortening increased significantly with a mean difference of 7.9%, 95% CI [4.8, 10.9], (P < 0.0001). Cardiac troponin I was not different at pre- and immediately post-race time points, but was significantly increased at T4 (P < 0.001). Troponin returned to baseline value by T24. Conclusions This study utilized a before and after study design where each horse served as its own control, as such the possible effect of regression to the mean cannot be ruled out. The reference intervals generated in this study may be used to identify selected echocardiographic and electrocardiographic abnormalities in racing horses receiving furosemide.
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Affiliation(s)
- Catherine T Gunther-Harrington
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA
| | - Rick Arthur
- School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA
| | - Krista Estell
- William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), University of California Davis, Davis, CA, 95616, USA.,Present Address: Marion duPont Scott Equine Medical Center, Virginia-Maryland College of Veterinary Medicine, Leesburg, VA, 20176, USA
| | - Beatriz Martinez Lopez
- Center for Animal Disease Modeling And Surveillance (CADMS), Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA
| | - Alexandra Sinnott
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA
| | - Eric Ontiveros
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA
| | - Anita Varga
- William R. Pritchard Veterinary Medical Teaching Hospital (VMTH), University of California Davis, Davis, CA, 95616, USA.,Present Address: Gold Coast Veterinary Service & Consulting, Esparto, CA, 95627, USA
| | - Joshua A Stern
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA, 95616, USA.
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Shields E, Seiden-Long I, Massie S, Leguillette R. 24-Hour Kinetics of Cardiac Troponin-T Using a "High-Sensitivity" Assay in Thoroughbred Chuckwagon Racing Geldings after Race and Associated Clinical Sampling Guidelines. J Vet Intern Med 2017; 32:433-440. [PMID: 29171090 PMCID: PMC5787185 DOI: 10.1111/jvim.14870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 08/28/2017] [Accepted: 10/11/2017] [Indexed: 12/04/2022] Open
Abstract
Background A “high‐sensitivity” cardiac troponin‐T (hscTnT) assay recently has been validated for use in horses and is a specific biomarker of myocardial damage. Postexercise release kinetics of cTnT utilizing the hscTnT assay have yet to be established in horses. Objectives To determine: (1) cTnT release kinetics in racing Thoroughbreds after a high‐intensity 5/8th mile Chuckwagon race; (2) the effects of age on pre‐ and postrace cTnT concentrations; and (3) sampling guidelines for clinicians evaluating horses presenting after exercise. Animals Samples were obtained from 38 Thoroughbred geldings aged 5–16 years before racing and immediately, 2, 3, 4, 6, 12, and 24 hour postrace. Methods Prospective, observational study with convenience sampling. A fifth‐generation hscTnT assay was used for plasma sample analysis, and concentrations were compared at all time‐points. Correlations were determined between cTnT concentrations and age. Biochemistry analysis was performed to assess rhabdomyolysis, renal failure, and exercise‐induced dehydration. Results All horses with measureable cTnT concentrations had significant postexercise increases in cTnT with a median peak (8.0 ng/L) at 3‐hour postrace. All horses had peak postexercise cTnT concentrations 2‐ to 6‐hour postrace ≤ the 99th percentile upper reference limit of 23.2 ng/L, after which all cTnT concentrations decreased until returning to baseline by 12–24 hours. There was no correlation over time between cTnT concentrations and age. Conclusions and Clinical Importance In racing Thoroughbreds completing short‐duration, high‐intensity Chuckwagon races, cTnT concentrations are expected to be increased 2‐ to 6‐hour postrace and to decrease by 12–24 hours while remaining ≤23.2 ng/L throughout. This study contributes to establishing guidelines for clinical use of the hscTnT assay in exercising horses.
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Affiliation(s)
- E Shields
- Faculty of Veterinary Medicine (UCVM), University of Calgary, Calgary, Alberta, Canada
| | - I Seiden-Long
- Faculty of Medicine and Calgary Lab Services (CLS), University of Calgary, Calgary, Alberta, Canada
| | - S Massie
- Faculty of Veterinary Medicine (UCVM), University of Calgary, Calgary, Alberta, Canada
| | - R Leguillette
- Faculty of Veterinary Medicine (UCVM), University of Calgary, Calgary, Alberta, Canada
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Wijnberg I, Franklin S. The heart remains the core: cardiac causes of poor performance in horses compared to human athletes. COMPARATIVE EXERCISE PHYSIOLOGY 2017. [DOI: 10.3920/cep170012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cardiac remodelling occurs in response to exercise and is generally beneficial for athletic performance due to the increase in cardiac output. However, this remodelling also may lead to an increased prevalence of cardiac murmurs and arrhythmias. In most cases, these are not considered to be significant. However, in some cases, there may be potentially deleterious consequences. Whilst sudden cardiac death (SCD) is a rare occurrence, the consequences are catastrophic for both the horse and potentially the rider or driver. Furthermore, the sudden death of a horse in the public arena has negative connotations in regards to public perception of welfare during equestrian sports. Prediction of which individuals might be susceptible to potential deleterious effects of exercise is a focus of interest in both human and equine athletes but remains a challenge because many athletes experience cardiac murmurs and exercise-induced arrhythmias that are clinically irrelevant. This review summarises the effects of exercise on cardiac remodelling in the horse and the potential effects on athletic performance and SCD. The use of biomarkers and their future potential in the management of athletic horses is also reviewed.
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Affiliation(s)
- I.D. Wijnberg
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 114, 3584 CM, Utrecht, the Netherlands
| | - S.H. Franklin
- Equine Health and Performance Centre, School of Animal and Veterinary Science, University of Adelaide, SA 5005, Australia
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Lorello O, Ramseyer A, Burger D, Gerber V, Bruckmaier RM, van der Kolk JH, Navas de Solis C. Repeated Measurements of Markers of Autonomic Tone Over a Training Season in Eventing Horses. J Equine Vet Sci 2017. [DOI: 10.1016/j.jevs.2017.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Kraus M, Physick-Sheard PW, Brito LF, Schenkel FS. Estimates of heritability of atrial fibrillation in the Standardbred racehorse. Equine Vet J 2017; 49:718-722. [DOI: 10.1111/evj.12687] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 04/04/2017] [Indexed: 11/29/2022]
Affiliation(s)
- M. Kraus
- Department of Animal Biosciences; Guelph Ontario Canada
| | | | - L. F. Brito
- Department of Animal Biosciences; Guelph Ontario Canada
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Abstract
Postmortem lesions and cause of death were evaluated retrospectively for 963 horses examined as part of the Ontario Racing Commission Death Registry over a 13-y period. The Death Registry was established in 2003 to identify factors leading to death or euthanasia of racehorses in this Canadian province. Postmortem examination was carried out on 56% of horses reported to the Death Registry and included Standardbred, Thoroughbred, and American Quarter Horses. Musculoskeletal injury was the most common reason for death associated with racing or training among all racehorses and involved 68% of horses. A history of sudden death during or immediately following exercise was described for 31% of racing- or training-associated deaths, and in 16% of all horses in the study. Sudden death occurred in horses of all breeds, and our report describes lesions associated with sudden death in a series of Standardbreds. The cause of death in these cases was most frequently attributed to cardiopulmonary lesions. The cause of death was undetermined in 20% of sudden death cases, and it is speculated that cardiac arrhythmia may have contributed to these deaths. Injection-associated death was documented in 4% of the study population. Lesions among horses whose death was not associated with exercise were similar to those in other equine populations, and lesions involving the gastrointestinal system were most common. Standardization of pathology reporting of pulmonary and other lesions in racehorse postmortem cases would allow direct comparison of results among racehorse populations.
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Affiliation(s)
- Josepha DeLay
- Animal Health Laboratory, Laboratory Services Division, University of Guelph, Guelph, Ontario, Canada
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46
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Flethøj M, Kanters JK, Pedersen PJ, Haugaard MM, Carstensen H, Olsen LH, Buhl R. Appropriate threshold levels of cardiac beat-to-beat variation in semi-automatic analysis of equine ECG recordings. BMC Vet Res 2016; 12:266. [PMID: 27894294 PMCID: PMC5126988 DOI: 10.1186/s12917-016-0894-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/22/2016] [Indexed: 11/24/2022] Open
Abstract
Background Although premature beats are a matter of concern in horses, the interpretation of equine ECG recordings is complicated by a lack of standardized analysis criteria and a limited knowledge of the normal beat-to-beat variation of equine cardiac rhythm. The purpose of this study was to determine the appropriate threshold levels of maximum acceptable deviation of RR intervals in equine ECG analysis, and to evaluate a novel two-step timing algorithm by quantifying the frequency of arrhythmias in a cohort of healthy adult endurance horses. Results Beat-to-beat variation differed considerably with heart rate (HR), and an adaptable model consisting of three different HR ranges with separate threshold levels of maximum acceptable RR deviation was consequently defined. For resting HRs <60 beats/min (bpm) the threshold level of RR deviation was set at 20%, for HRs in the intermediate range between 60 and 100 bpm the threshold was 10%, and for exercising HRs >100 bpm, the threshold level was 4%. Supraventricular premature beats represented the most prevalent arrhythmia category with varying frequencies in seven horses at rest (median 7, range 2–86) and six horses during exercise (median 2, range 1–24). Conclusions Beat-to-beat variation of equine cardiac rhythm varies according to HR, and threshold levels in equine ECG analysis should be adjusted accordingly. Standardization of the analysis criteria will enable comparisons of studies and follow-up examinations of patients. A small number of supraventricular premature beats appears to be a normal finding in endurance horses. Further studies are required to validate the findings and determine the clinical significance of premature beats in horses.
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Affiliation(s)
- Mette Flethøj
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Hoejbakkegaard Allé 5, 2630, Taastrup, Denmark.
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark.,Department of Cardiology, Herlev & Gentofte University Hospitals, Copenhagen, Denmark
| | - Philip J Pedersen
- Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlaegevej 100, 1870, Frederiksberg C, Denmark
| | - Maria M Haugaard
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Hoejbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Helena Carstensen
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Hoejbakkegaard Allé 5, 2630, Taastrup, Denmark
| | - Lisbeth H Olsen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Groennegaardsvej 15, 1870, Frederiksberg C, Denmark
| | - Rikke Buhl
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Hoejbakkegaard Allé 5, 2630, Taastrup, Denmark
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48
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Navas de Solis C. Exercising arrhythmias and sudden cardiac death in horses: Review of the literature and comparative aspects. Equine Vet J 2016; 48:406-13. [DOI: 10.1111/evj.12580] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 03/28/2016] [Indexed: 12/25/2022]
Affiliation(s)
- C. Navas de Solis
- Swiss Institute of Equine Medicine; Faculty of Veterinary Science (Vetsuisse); University of Bern and Agroscope; Bern Switzerland
- Texas Veterinary Medical Center; Texas A&M University; College Station USA
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49
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Flethøj M, Kanters JK, Haugaard MM, Pedersen PJ, Carstensen H, Balling JD, Olsen LH, Buhl R. Changes in heart rate, arrhythmia frequency, and cardiac biomarker values in horses during recovery after a long-distance endurance ride. J Am Vet Med Assoc 2016; 248:1034-42. [DOI: 10.2460/javma.248.9.1034] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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50
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Physick-Sheard PW. Equine electrocardiography revisited. EQUINE VET EDUC 2016. [DOI: 10.1111/eve.12537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- P. W. Physick-Sheard
- Department of Population Medicine; Ontario Veterinary College; University of Guelph; Canada
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