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Kjeldsen ST, Nissen SD, Christensen NC, Haugaard SL, Schneider MJ, Vinther Z, Sattler SM, Carstensen H, Jøns C, Hopster‐Iversen C, Buhl R. Validation and clinical application of implantable loop recorders for diagnosis of atrial fibrillation in horses. Equine Vet J 2025; 57:449-458. [PMID: 39031582 PMCID: PMC11807927 DOI: 10.1111/evj.14112] [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: 01/04/2024] [Accepted: 05/16/2024] [Indexed: 07/22/2024]
Abstract
BACKGROUND Paroxysmal atrial fibrillation (pAF) occurs sporadically and can impair athletic performance. Gold standard for diagnosis is surface electrocardiography (ECG), however, this requires AF to be sustained. Implantable loop recorders (ILRs) are routinely used for AF detection in human medicine. While ILR placement has been studied in horses, its AF detection performance is unknown. OBJECTIVES (I) Validation of ILRs for AF detection in horses. (II) Determining pAF incidence using ILRs and estimate the positive predictive value (PPV). STUDY DESIGN (I) Experimental study; (II) Longitudinal observational study. METHODS (I) Implantation of ILRs in 15 horses with AF and 13 horses in sinus rhythm. Holter ECGs were recorded at: 1, 4, 8, 12 and 16 weeks of AF. The ILR ECGs were compared with surface ECGs to assess diagnostic sensitivity and specificity. (II) Eighty horses (43 Warmbloods, 37 Standardbreds) with ILRs were monitored for 367 days [IQR 208-621]. RESULTS (I) ILRs detected AF on all recording days, in horses with AF, with a sensitivity of 66.1% (95% CI: 65.8-66.5) and a specificity of 99.99% (95% CI: 99.97-99.99). The sensitivity remained consistent across all time points. (II) The incidence of pAF was 6.3% (5/80). In horses with pAF, the PPV ranged from 8% to 87%. Increased body condition score (BCS > 6/9) was associated with an increased number of false positive episodes (p = 0.005). MAIN LIMITATIONS (I) Horses were stabled during the ECG recordings, and AF was induced, rather than naturally occurring pAF. (II) Integrated algorithm in this ILR is optimised for AF detection in humans using remote monitors. Additionally, sensing is affected by motion artefacts. CONCLUSION The ILR reliably detected AF in resting horses, particularly in horses with normal BCS (6/9). The ILR proved useful to detect pAF and is recommended alongside Holter monitoring for diagnostic workup of horses with suspected pAF.
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Affiliation(s)
- Sofie Troest Kjeldsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Sarah D. Nissen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Nina C. Christensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Simon L. Haugaard
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Mélodie J. Schneider
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Zenta Vinther
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Stefan M. Sattler
- Department of CardiologyHerlev and Gentofte University HospitalGentofteDenmark
- Department of Biomedical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Christian Jøns
- Department of Cardiology, The Heart CentreCopenhagen University Hospital, RigshospitaletCopenhagenDenmark
| | - Charlotte Hopster‐Iversen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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Colgate VA. IFHA Global Summit on Equine Safety and Technology: Reducing the risk of Exercise Associated Sudden Death. Equine Vet J 2025; 57:296-302. [PMID: 39665287 DOI: 10.1111/evj.14448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2024] [Accepted: 11/12/2024] [Indexed: 12/13/2024]
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Vernemmen I, Van Steenkiste G, Buschmann E, Cornelis K, Schauvliege S, Ibrahim L, Decloedt A, van Loon G. Development of an atrial transseptal puncture procedure in horses to access the left heart: An ultrasound-guided jugular vein and transhepatic approach. Equine Vet J 2025; 57:243-255. [PMID: 38522423 DOI: 10.1111/evj.14084] [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: 12/01/2023] [Accepted: 02/25/2024] [Indexed: 03/26/2024]
Abstract
BACKGROUND Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein. OBJECTIVES To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach. STUDY DESIGN In vivo experimental study. METHODS Transseptal puncture was performed in 18 horses admitted for euthanasia and donated for scientific research under general anaesthesia: using a jugular vein approach (10 horses), a transhepatic approach (2 horses) or both (6 horses). Radiofrequency energy was applied on a guidewire to perforate the FO and allow sheath advancement under intracardiac and transthoracic echocardiographic guidance. Puncture lesions were inspected post-mortem. RESULTS Transseptal puncture was successful in 17/18 horses, of which 15/16 jugular vein approaches and 5/8 transhepatic approaches. Failure was due to technical malfunction, inability to advance the guidewire toward the heart and inability to advance the sheath through the FO. Intracardiac echocardiography was essential to safely guide the puncture process. Atrial arrhythmias caused by the TSP occurred in 13/18 horses. Puncture lesions were found in the right atrium in the FO region, and left atrium ventral to pulmonary vein ostium III. MAIN LIMITATIONS Because in several horses two approaches were tested consecutively, it cannot be excluded that the second TSP was performed at the previous puncture site. Due to the developmental nature of the study the approaches were not randomised and did not allow comparison. CONCLUSION Transseptal puncture is feasible in horses using ultrasound guidance and allows for electrophysiological exploration of the left heart. Further studies are needed to evaluate post-operative follow-up.
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Affiliation(s)
- Ingrid Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Kristoff Cornelis
- Cardiology Department, Maria Middelares Heart Centre, Ghent, Belgium
| | - Stijn Schauvliege
- Department of Surgery and Anaesthesiology of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Lara Ibrahim
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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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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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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Vernemmen I, Van Steenkiste G, Decloedt A, Meert H, Walser U, van Loon G. Detection of paroxysmal atrial fibrillation preceding persistent atrial fibrillation in a horse using an implantable loop recorder with remote monitoring. J Vet Cardiol 2024; 52:19-27. [PMID: 38402667 DOI: 10.1016/j.jvc.2024.02.002] [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: 09/28/2023] [Revised: 02/02/2024] [Accepted: 02/04/2024] [Indexed: 02/27/2024]
Abstract
Implantable loop recorders (ILRs) are increasingly used in equine cardiology to detect arrhythmias in the context of collapse, poor performance or monitoring for recurrence of atrial fibrillation (AF). However to date, the ILR has never been reported to be used with a remote monitoring functionality in horses, therefore the arrhythmia is only discovered when a clinician interrogates the ILR using dedicated equipment, which might delay diagnosis and intervention. This case report describes the use of an ILR with remote monitoring functionality in a horse with recurrent AF. The remote monitoring consisted of a transmission device located in the stable allowing daily transmission of arrhythmia recordings and functioning messages to an online server, available for the clinician to evaluate without specialised equipment. The ILR detected an episode of paroxysmal AF approximately 3 months after implantation. Seven months after implantation, initiation of persistent AF was seen on an episode misclassified by the ILR as bradycardia, and the horse was retired. This report shows the feasibility and benefits of remote monitoring for ILRs in horses, but also the shortcomings of current algorithms to interpret the equine electrocardiogram.
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Affiliation(s)
- I Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
| | - G Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - A Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - H Meert
- Biotronik Belgium, Medialaan 36, 1800 Vilvoorde, Belgium
| | - U Walser
- Biotronik Belgium, Medialaan 36, 1800 Vilvoorde, Belgium
| | - G van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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7
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Nath LC, Elliott A, La Gerche A, Weir J, Forbes G, Thomas G, Franklin S. Associations between postrace atrial fibrillation and measures of performance, racing history and airway disease in horses. J Vet Intern Med 2023; 37:2573-2583. [PMID: 37740606 PMCID: PMC10658555 DOI: 10.1111/jvim.16878] [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: 11/27/2022] [Accepted: 09/11/2023] [Indexed: 09/24/2023] Open
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common performance limiting arrhythmia in racehorses. High dose exercise and airway disease promote AF in humans. Few studies have investigated epidemiological factors associated with AF in horses. OBJECTIVES Explore variables relating to performance, exercise volume and postrace endoscopic findings in horses with AF. ANIMALS A total of 164 horses with poor race performance and postrace AF were compared to 321 horses with poor performance without AF (PP) and 314 horses performing to expectation (TE). METHODS Horse-level and race-level variables for horses racing in Australia and Hong Kong from 2009 to 2021 were compared using univariable and multivariable logistic regression. Postrace endoscopic exercise-induced pulmonary hemorrhage (EIPH) and tracheal mucus accumulation (TMA) grades for AF and PP horses were compared using chi-squared analysis. RESULTS Variables that were significant in the multivariable model of AF compared to TE were distance (lengths) behind the winner, (odds ratio [OR]; 95% confidence interval [95% CI], 1.41 [1.32-1.51], P < .0001), cumulative prize money per start before the event (OR [95% CI] 1.02 [1.01-1.03], P = .01) and age (OR [95% CI] 0.72 [0.55-0.92], P = .01). More AF horses had EIPH grade ≥ 3 (23/109; 21.1%) than PP horses (7/213; 3.3%; OR [95%CI] 7.9 [3.3-20.2], P < .0001). CONCLUSIONS AND CLINICAL IMPORTANCE Acute race performance was substantially impaired by AF but career earnings before the event were not inferior. Exercise volume did not promote AF. Higher grades of EIPH found in AF horses suggests a mechanistic relationship between these conditions.
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Assessment of P Wave Indices in Healthy Standardbred Horses. Animals (Basel) 2023; 13:ani13061070. [PMID: 36978611 PMCID: PMC10044338 DOI: 10.3390/ani13061070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/11/2023] [Accepted: 03/11/2023] [Indexed: 03/18/2023] Open
Abstract
P wave indices are used as non-invasive electrocardiographic markers of atrial remodelling in humans. Few studies have investigated their use in animals. The aim of this study was to measure P wave duration and P wave dispersion (Pd) in healthy standardbred horses and investigate variables that might influence these measurements. A 12-lead electrocardiogram was recorded at rest and P wave indices were calculated in 53 horses. A general linear model was used to investigate the main effects: age, bodyweight, sex, resting heart rate, presence of a murmur, exercise status and the number of years raced. There were significant associations with exercise status for both the maximum P wave duration and Pd, with both values being increased in strenuously exercising versus non-active horses. Furthermore, a significant moderate positive correlation was identified between the duration of exercise (number of years raced) and both Pmax and Pd. No other significant associations were identified. These findings are similar to those reported in elite human athletes versus sedentary individuals. The increases in these P wave indices most likely occur due to prolongation and heterogeneity in atrial conduction time, which are associated with structural and electrical remodelling, and may explain the increased risk of atrial fibrillation in athletic horses.
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9
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Decloedt A. Implantable loop recorders for detecting arrhythmia in horses: Research tool or diagnostic technique? EQUINE VET EDUC 2023. [DOI: 10.1111/eve.13778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine Ghent University Merelbeke Belgium
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Kjeldsen ST, Jensen M, Sørensen CT, Hopster‐Iversen C, Nissen SD. Long‐term monitoring with an implantable loop recorder detects multiple episodes of paroxysmal atrial fibrillation after electrical cardioversion in a Warmblood horse. EQUINE VET EDUC 2022. [DOI: 10.1111/eve.13745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sofie Troest Kjeldsen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Taastrup Denmark
| | - Maria Jensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Taastrup Denmark
| | - Carina Thermann Sørensen
- 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
| | - Sarah Dalgas Nissen
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences University of Copenhagen Copenhagen Denmark
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Paroxysmal Atrial Fibrillation in Horses: Pathophysiology, Diagnostics and Clinical Aspects. Animals (Basel) 2022; 12:ani12060698. [PMID: 35327097 PMCID: PMC8944606 DOI: 10.3390/ani12060698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 02/07/2023] Open
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in horses causing poor performance. As in humans, the condition can be intermittent in nature, known as paroxysmal atrial fibrillation (pAF). This review covers the literature relating to pAF in horses and includes references to the human literature to compare pathophysiology, clinical presentation, diagnostic tools and treatment. The arrhythmia is diagnosed by auscultation and electrocardiography (ECG), and clinical signs can vary from sudden loss of racing performance to reduced fitness or no signs at all. If left untreated, pAF may promote electrical, functional and structural remodeling of the myocardium, thus creating a substrate that is able to maintain the arrhythmia, which over time may progress into permanent AF. Long-term ECG monitoring is essential for diagnosing the condition and fully understanding the duration and frequency of pAF episodes. The potential to adapt human cardiac monitoring systems and computational ECG analysis is therefore of interest and may benefit future diagnostic tools in equine medicine.
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12
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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: 1.7] [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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Luethy D, Robinson MA, Stefanovski D, Haughan J, Torcivia C, Kowalski A, Ford M, You Y, Missanelli J, Slack J. Pharmacokinetics and pharmacodynamics of oral and intravenous metoprolol tartrate in clinically healthy horses. J Vet Pharmacol Ther 2021; 45:177-187. [PMID: 34913168 DOI: 10.1111/jvp.13037] [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: 08/13/2021] [Revised: 11/17/2021] [Accepted: 12/04/2021] [Indexed: 11/30/2022]
Abstract
Cardiac drugs with defined pharmacological parameters in horses are limited. The objective of this study was to characterize the pharmacokinetic properties and cardiovascular effects of intravenous and oral metoprolol tartrate (MET) in horses. In a 2-period randomized cross-over design, MET was administered IV (0.04 mg/kg) and PO (6 mg/kg) once to six healthy adult horses. Horses were monitored via continuous telemetry and non-invasive blood pressure (NIBP). Blood samples were serially collected for 72 h post-administration, and concentrations were determined by LC-MS/MS. Pharmacokinetics were modeled using a 3-compartment model and non-linear least squares regression. Median (range) MET concentration was 110 (40.1-197) ng/ml collected 1 min (0.0167 h) after a bolus IV administration. Maximum concentration (Cmax ) after PO administration was 2135 (1590-4170) ng/ml at 0.5 (0.25-0.5) hours. Oral bioavailability was 54% (17-100%). Median apparent volume of distribution was 0.39 (0.17-0.58) l/kg, clearance was 12.63 (11.41-18.94) ml/kg/min, and elimination half-life was 21.1 (7.46-34.36) minutes. No clinically relevant effects of IV or PO metoprolol were noted on cardiac rhythm or NIBP. Sweating was the most common side effect. The metoprolol doses used in this study achieve plasma concentrations reported to achieve ß-blockade in humans.
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Affiliation(s)
- Daniela Luethy
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.,Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Mary A Robinson
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA.,Pennsylvania Equine Toxicology and Research Lab, School of Veterinary Medicine, University of Pennsylvania, West Chester, Pennsylvania, USA
| | - Darko Stefanovski
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Joanne Haughan
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Catherine Torcivia
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Alycia Kowalski
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Matthew Ford
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
| | - Youwen You
- Pennsylvania Equine Toxicology and Research Lab, School of Veterinary Medicine, University of Pennsylvania, West Chester, Pennsylvania, USA
| | - Jaclyn Missanelli
- Pennsylvania Equine Toxicology and Research Lab, School of Veterinary Medicine, University of Pennsylvania, West Chester, Pennsylvania, USA
| | - Joann Slack
- Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, Pennsylvania, USA
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14
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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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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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16
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Wright S. Highlights of recent clinically relevant papers. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13497] [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]
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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: 17] [Impact Index Per Article: 4.3] [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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