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Triguinho A, Fontes-Sousa AP, Pimenta J, Cotovio M. Electrocardiographic Reference Values in Clinically Healthy Lusitano Horses. Vet Sci 2023; 10:518. [PMID: 37624305 PMCID: PMC10459813 DOI: 10.3390/vetsci10080518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/25/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
The Lusitano horse is gaining popularity in the equestrian world, and as a result, the significance of applied sports medicine for this breed is growing. As cardiology plays a crucial role in this field, numerous studies have been conducted to establish electrocardiographic reference values in various breeds to ensure a more accurate evaluation. However, studies regarding healthy Lusitano horses are lacking. So, this study aimed to establish electrocardiographic reference values for Lusitano horses, utilizing a sample of 82 clinically healthy animals. The evaluation involved lead II and base-apex lead measurements, with a median heart rate of 39 beats per minute being recorded. The P wave demonstrated a predominantly bifid configuration, while the QRS complex exhibited various forms. The most common QRS configurations were QR and R in lead II, and RS in the base-apex lead. Additionally, most T waves displayed a biphasic shape in both methods. Furthermore, statistically significant differences were noted based on age and gender. Some of the electrocardiographic values obtained differed from those previously published for other breeds. Given the relevance of electrocardiogram in cardiovascular evaluation, these findings bring valuable insights regarding the specific parameters for Lusitano horse and emphasize the importance of obtaining breed-specific electrocardiographic reference values.
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Affiliation(s)
- Alexandre Triguinho
- Independent Veterinary Care, Chapelfield Veterinary Partnership, Brooke Equine Clinic, Bungay Road, Brooke, Norwich NR15 1DX, UK
| | - Ana Patrícia Fontes-Sousa
- Department of Immuno-Physiology and Pharmacology, Abel Salazar Institute of Biomedical Sciences, University of Porto (ICBAS-UP), 4050-313 Porto, Portugal
- Center for Drug Discovery and Innovative Medicines (MedInUP), Abel Salazar Institute of Biomedical Sciences, University of Porto (ICBAS-UP), 4050-313 Porto, Portugal
- UPVET, Veterinary Hospital of Abel Salazar Institute of Biomedical Sciences, University of Porto (ICBAS-UP), 4050-313 Porto, Portugal
| | - José Pimenta
- Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro (UTAD), 5001-801 Vila Real, Portugal
- CECAV—Veterinary and Animal Research Center, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Vila Real, Portugal
| | - Mário Cotovio
- Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro (UTAD), 5001-801 Vila Real, Portugal
- CECAV—Veterinary and Animal Research Center, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal
- Associate Laboratory for Animal and Veterinary Sciences (AL4AnimalS), 5000-801 Vila Real, Portugal
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2
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Buhl R, Hesselkilde EM, Carstensen H, Hopster‐Iversen C, van Loon G, Decloedt A, Van Steenkiste G, Marr C, Reef VB, Schwarzwald CC, Mitchell KJ, Nostell K, Nogradi N, Nielsen SS, Carlson J, Platonov P. Atrial fibrillatory rate as predictor of recurrence of atrial fibrillation in horses treated medically or with electrical cardioversion. Equine Vet J 2022; 54:1013-1022. [PMID: 34957586 PMCID: PMC9787611 DOI: 10.1111/evj.13551] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 12/20/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND The recurrence rate of atrial fibrillation (AF) in horses after cardioversion to sinus rhythm (SR) is relatively high. Atrial fibrillatory rate (AFR) derived from surface ECG is considered a biomarker for electrical remodelling and could potentially be used for the prediction of successful AF cardioversion and AF recurrence. OBJECTIVES Evaluate if AFR was associated with successful treatment and could predict AF recurrence in horses. STUDY DESIGN Retrospective multicentre study. METHODS Electrocardiograms (ECG) from horses with persistent AF admitted for cardioversion with either medical treatment (quinidine) or transvenous electrical cardioversion (TVEC) were included. Bipolar surface ECG recordings were analysed by spatiotemporal cancellation of QRST complexes and calculation of AFR from the remaining atrial signal. Kaplan-Meier survival curve and Cox regression analyses were performed to assess the relationship between AFR and the risk of AF recurrence. RESULTS Of the 195 horses included, 74 received quinidine treatment and 121 were treated with TVEC. Ten horses did not cardiovert to SR after quinidine treatment and AFR was higher in these, compared with the horses that successfully cardioverted to SR (median [interquartile range]), (383 [367-422] vs 351 [332-389] fibrillations per minute (fpm), P < .01). Within the first 180 days following AF cardioversion, 12% of the quinidine and 34% of TVEC horses had AF recurrence. For the horses successfully cardioverted with TVEC, AFR above 380 fpm was significantly associated with AF recurrence (hazard ratio = 2.4, 95% confidence interval 1.2-4.8, P = .01). MAIN LIMITATIONS The treatment groups were different and not randomly allocated, therefore the two treatments cannot be compared. Medical records and the follow-up strategy varied between the centres. CONCLUSIONS High AFR is associated with failure of quinidine cardioversion and AF recurrence after successful TVEC. As a noninvasive marker that can be retrieved from surface ECG, AFR can be clinically useful in predicting the probability of responding to quinidine treatment as well as maintaining SR after electrical cardioversion.
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Affiliation(s)
- Rikke Buhl
- Department of Veterinary Clinical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Eva M. Hesselkilde
- Department of Veterinary Clinical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Helena Carstensen
- Department of Veterinary Clinical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Charlotte Hopster‐Iversen
- Department of Veterinary Clinical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Gunther van Loon
- Equine CardioteamDepartment of Large Animal Internal MedicineGhent UniversityMerelbekeBelgium
| | - Annelies Decloedt
- Equine CardioteamDepartment of Large Animal Internal MedicineGhent UniversityMerelbekeBelgium
| | - Glenn Van Steenkiste
- Equine CardioteamDepartment of Large Animal Internal MedicineGhent UniversityMerelbekeBelgium
| | | | - Virginia B. Reef
- Department of Clinical Studies New Bolton CenterUniversity of Pennsylvania School of Veterinary MedicineKennett SquarePennsylvaniaUSA
| | | | | | - Katarina Nostell
- Department of Clinical SciencesFaculty of Veteirnary SciencesSwedish University of Agricultural SciencesUppsalaSweden
| | | | - Søren S. Nielsen
- Department of Veterinary SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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3
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Asorey I, Corletto F. Anaesthetic management of a horse with atrial fibrillation undergoing transvenous electrical cardioversion in combination with amiodarone. VETERINARY RECORD CASE REPORTS 2022. [DOI: 10.1002/vrc2.495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Federico Corletto
- Dick White Referrals Six Mile Bottom UK
- Newmarket Equine Hospital Newmarket UK
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4
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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: 2.0] [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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5
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Premont A, Balthes S, Marr CM, Jeevaratnam K. Fundamentals of arrhythmogenic mechanisms and treatment strategies for equine atrial fibrillation. Equine Vet J 2021; 54:262-282. [PMID: 34564902 DOI: 10.1111/evj.13518] [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: 12/21/2020] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 11/26/2022]
Abstract
Atrial fibrillation (AF) is the most common pathological arrhythmia in horses. Although it is not usually a life-threatening condition on its own, it can cause poor performance and make the horse unsafe to ride. It is a complex multifactorial disease influenced by both genetic and environmental factors including exercise training, comorbidities or ageing. The interactions between all these factors in horses are still not completely understood and the pathophysiology of AF remains poorly defined. Exciting progress has been recently made in equine cardiac electrophysiology in terms of diagnosis and documentation methods such as cardiac mapping, implantable electrocardiogram (ECG) recording devices or computer-based ECG analysis that will hopefully improve our understanding of this disease. The available pharmaceutical and electrophysiological treatments have good efficacy and lead to a good prognosis for AF, but recurrence is a frequent issue that veterinarians have to face. This review aims to summarise our current understanding of equine cardiac electrophysiology and pathophysiology of equine AF while providing an overview of the mechanism of action for currently available treatments for equine AF.
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Affiliation(s)
- Antoine Premont
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Samantha Balthes
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Celia M Marr
- Rossdales Equine Hospital and Diagnostic Centre, Newmarket, UK
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Saljic A, Friederike Fenner M, Winters J, Flethøj M, Eggert Eggertsen C, Carstensen H, Dalgas Nissen S, Melis Hesselkilde E, van Hunnik A, Schotten U, Sørensen U, Jespersen T, Verheule S, Buhl R. Increased fibroblast accumulation in the equine heart following persistent atrial fibrillation. IJC HEART & VASCULATURE 2021; 35:100842. [PMID: 34355058 PMCID: PMC8322305 DOI: 10.1016/j.ijcha.2021.100842] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 06/30/2021] [Accepted: 07/06/2021] [Indexed: 01/06/2023]
Abstract
Persistent atrial fibrillation is associated with increased fibroblast accumulation. Six weeks of persistent AF is not associated with structural remodeling. Fibroblasts are potentially contributing to alteration in atrial electrophysiology.
Background Fibroblasts maintain the extracellular matrix homeostasis and may couple to cardiomyocytes through gap junctions and thereby increase the susceptibility to slow conduction and cardiac arrhythmias, such as atrial fibrillation (AF). In this study, we used an equine model of persistent AF to characterize structural changes and the role of fibroblasts in the development of an arrhythmogenic substrate for AF. Material and methods Eleven horses were subjected to atrial tachypacing until self-sustained AF developed and were kept in AF for six weeks. Horses in sinus rhythm (SR) served as control. In terminal open-chest experiments conduction velocity (CV) was measured. Tissue was harvested and stained from selected sites. Automated image analysis was performed to assess fibrosis, fibroblasts, capillaries and various cardiomyocyte characteristics. Results Horses in SR showed a rate-dependent slowing of CV, while in horses with persistent AF this rate-dependency was completely abolished (CV•basic cycle length relation p = 0.0295). Overall and interstitial amounts of fibrosis were unchanged, but an increased fibroblast count was found in left atrial appendage, Bachmann's bundle, intraatrial septum and pulmonary veins (p < 0.05 for all) in horses with persistent AF. The percentage of α-SMA expressing fibroblasts remained the same between the groups. Conclusion Persistent AF resulted in fibroblast accumulation in several regions, particularly in the left atrial appendage. The increased number of fibroblasts could be a mediator of altered electrophysiology during AF. Targeting the fibroblast proliferation and differentiation could potentially serve as a novel therapeutic target slowing down the structural remodeling associated with AF.
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Affiliation(s)
- Arnela Saljic
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Merle Friederike Fenner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Agrovej 8, DK-2630 Taastrup, Denmark.,Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Grønnegårdsvej 7, 1870 Frederiksberg, Denmark
| | - Joris Winters
- Department of Physiology, Maastricht University, Maastricht, Netherlands
| | - Mette Flethøj
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Agrovej 8, DK-2630 Taastrup, Denmark
| | - Caroline Eggert Eggertsen
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Agrovej 8, DK-2630 Taastrup, Denmark
| | - Sarah Dalgas Nissen
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Eva Melis Hesselkilde
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Arne van Hunnik
- Department of Physiology, Maastricht University, Maastricht, Netherlands
| | - Ulrich Schotten
- Department of Physiology, Maastricht University, Maastricht, Netherlands
| | | | - Thomas Jespersen
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen, Denmark
| | - Sander Verheule
- Department of Physiology, Maastricht University, Maastricht, Netherlands
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Agrovej 8, DK-2630 Taastrup, Denmark
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7
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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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8
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Woort F, Reef V, Stefanovski D, Slack J. Cardiac pre‐purchase examination in horses – evaluation, outcome and athletic follow‐up. EQUINE VET EDUC 2021. [DOI: 10.1111/eve.13507] [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)
- F. Woort
- Equine Sports Medicine Practice Waterloo Belgium
| | - V. Reef
- New Bolton Center University of Pennsylvania Kennett Square Pennsylvania USA
| | - D. Stefanovski
- New Bolton Center University of Pennsylvania Kennett Square Pennsylvania USA
| | - J. Slack
- New Bolton Center University of Pennsylvania Kennett Square Pennsylvania USA
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9
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Victorino J, Alvarez-Franco A, Manzanares M. Functional genomics and epigenomics of atrial fibrillation. J Mol Cell Cardiol 2021; 157:45-55. [PMID: 33887329 DOI: 10.1016/j.yjmcc.2021.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/07/2021] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
Atrial fibrillation is a progressive cardiac arrhythmia that increases the risk of hospitalization and adverse cardiovascular events. Despite years of study, we still do not have a full comprehension of the molecular mechanism responsible for the disease. The recent implementation of large-scale approaches in both patient samples, population studies and animal models has helped us to broaden our knowledge on the molecular drivers responsible for AF and on the mechanisms behind disease progression. Understanding genomic and epigenomic changes that take place during chronification of AF will prove essential to design novel treatments leading to improved patient care.
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Affiliation(s)
- Jesus Victorino
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de Madrid (UAM), Spain
| | - Alba Alvarez-Franco
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain
| | - Miguel Manzanares
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, Spain; Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain.
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De Lange L, Vera L, Decloedt A, Van Steenkiste G, Vernemmen I, van Loon G. Prevalence and characteristics of ventricular septal defects in a non-racehorse equine population (2008-2019). J Vet Intern Med 2021; 35:1573-1581. [PMID: 33742468 PMCID: PMC8163134 DOI: 10.1111/jvim.16106] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/01/2021] [Accepted: 03/03/2021] [Indexed: 11/29/2022] Open
Abstract
Background Ventricular septal defects (VSDs) are the most common congenital cardiac defect in horses. Objectives To identify prevalence, age, breed, and sex distribution of VSD and to describe associated clinical and ultrasonographic findings. Animals Hospital‐based population of 21 136 horses presented to the equine internal medicine department. Methods Medical records over a 12‐year period were reviewed for VSD confirmed by ultrasonography. Age, breed, sex, sport discipline, murmur, clinical signs, outcome, VSD type, VSD size, shunt velocity, cardiac dimensions, concomitant cardiac anomalies, and valvular regurgitations were recorded. Results From 1894 horses that underwent echocardiography, 54 had a VSD: 42 as an isolated lesion and 12 as part of complex congenital heart disease (CHD). Median age was 5 years (range, 0‐26) and 1 year (range, 0‐8), respectively. Warmbloods and males were overrepresented. In the isolated VSD group, only 15% had associated clinical signs and most horses had a perimembranous VSD (pmVSD; 36/42). Horses with a pmVSD and clinical signs showed a significantly lower maximal shunt velocity (3.77 vs 5.20 m/s; P < .001), higher VSD/Aortic root (Ao) diameter (0.52 vs 0.38; P = .05), higher left atrium/Ao diameter (1.94 vs 1.22; P < .001), and higher pulmonary artery/Ao diameter (1.15 vs 0.88; P = .005) compared to horses without clinical signs. All horses with complex CHD had clinical signs and abnormal cardiac dimensions. Conclusion and Clinical Importance Most isolated VSD were diagnosed only at a later age and were not associated with clinical signs. Horses with complex CHD were more likely to have or develop clinical signs at younger age.
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Affiliation(s)
- Lisa De Lange
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Lisse Vera
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Annelies Decloedt
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Glenn Van Steenkiste
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ingrid Vernemmen
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gunther van Loon
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Saljic A, Jespersen T, Buhl R. Anti-arrhythmic investigations in large animal models of atrial fibrillation. Br J Pharmacol 2021; 179:838-858. [PMID: 33624840 DOI: 10.1111/bph.15417] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/10/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022] Open
Abstract
Atrial fibrillation (AF) constitutes an increasing health problem in the aging population. Animal models reflecting human phenotypes are needed to understand the mechanisms of AF, as well as to test new pharmacological interventions. In recent years, a number of large animal models, primarily pigs, goats, dog and horses have been used in AF research. These animals can to a certain extent recapitulate the human pathophysiological characteristics and serve as valuable tools in investigating new pharmacological interventions for treating AF. This review focuses on anti-arrhythmic investigations in large animals. Initially, spontaneous AF in small and large mammals is discussed. This is followed by a short presentation of frequently used methods for inducing short- and long-term AF. The major focus of the review is on anti-arrhythmic compounds either frequently used in the human clinic (ranolazine, flecainide, vernakalant and amiodarone) or being promising new AF medicine candidates (IK,Ach , ISK,Ca and IK2P blockers).
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Affiliation(s)
- Arnela Saljic
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Jespersen
- Laboratory of Cardiac Physiology, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
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12
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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: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [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 Sciences, University of Adelaide, Roseworthy, South Australia, Australia
| | - Adrian D Elliott
- Centre for Heart Rhythm Disorders, Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Joe Weir
- Hong Kong Jockey Club, Veterinary Clinical Services, Equine Hospital, Hong Kong SAR, Hong Kong
| | - Peter Curl
- Veterinary Regulation, Hong Kong Jockey Club, Hong Kong SAR, Hong Kong
| | | | - Samantha Franklin
- School of Animal & Veterinary Sciences, University of Adelaide, Roseworthy, South Australia, Australia
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Huang YH, Alexeenko V, Tse G, Huang CLH, Marr CM, Jeevaratnam K. ECG Restitution Analysis and Machine Learning to Detect Paroxysmal Atrial Fibrillation: Insight from the Equine Athlete as a Model for Human Athletes. FUNCTION (OXFORD, ENGLAND) 2020; 2:zqaa031. [PMID: 35330977 PMCID: PMC8788737 DOI: 10.1093/function/zqaa031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 01/06/2023]
Abstract
Atrial fibrillation is the most frequent arrhythmia in both equine and human athletes. Currently, this condition is diagnosed via electrocardiogram (ECG) monitoring which lacks sensitivity in about half of cases when it presents in paroxysmal form. We investigated whether the arrhythmogenic substrate present between the episodes of paroxysmal atrial fibrillation (PAF) can be detected using restitution analysis of normal sinus-rhythm ECGs. In this work, ECG recordings were obtained during routine clinical work from control and horses with PAF. The extracted QT, TQ, and RR intervals were used for ECG restitution analysis. The restitution data were trained and tested using k-nearest neighbor (k-NN) algorithm with various values of neighbors k to derive a discrimination tool. A combination of QT, RR, and TQ intervals was used to analyze the relationship between these intervals and their effects on PAF. A simple majority vote on individual record (one beat) classifications was used to determine the final classification. The k-NN classifiers using two-interval measures were able to predict the diagnosis of PAF with area under the receiving operating characteristic curve close to 0.8 (RR, TQ with k ≥ 9) and 0.9 (RR, QT with k ≥ 21 or TQ, QT with k ≥ 25). By simultaneously using all three intervals for each beat and a majority vote, mean area under the curves of 0.9 were obtained for all tested k-values (3-41). We concluded that 3D ECG restitution analysis can potentially be used as a metric of an automated method for screening of PAF.
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Affiliation(s)
- Ying H Huang
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK
| | - Vadim Alexeenko
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, the Second Hospital of Tianjin Medical University, Tianjin, China
| | - Christopher L-H Huang
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK,Physiological Laboratory, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Celia M Marr
- Rossdales Equine Hospital and Diagnostic Centre, Exning, CB8 7NN, Suffolk, UK
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7AL, UK,Physiological Laboratory, University of Cambridge, Cambridge, CB2 1QW, UK,Address correspondence to K.J. (e-mail: )
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14
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Decloedt A, Van Steenkiste G, Vera L, Buhl R, van Loon G. Atrial fibrillation in horses part 1: Pathophysiology. Vet J 2020; 263:105521. [PMID: 32928494 DOI: 10.1016/j.tvjl.2020.105521] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 07/05/2020] [Accepted: 07/21/2020] [Indexed: 01/30/2023]
Abstract
Atrial fibrillation (AF) is the most common clinically relevant arrhythmia in horses, with a reported prevalence up to 2.5%. The pathophysiology has mainly been investigated in experimental animal models and human medicine, with limited studies in horses. Atrial fibrillation results from the interplay between electrical triggers and a susceptible substrate. Triggers consist of atrial premature depolarizations due to altered automaticity or triggered activity, or local (micro)reentry. The arrhythmia is promoted by atrial myocardial ion channel alterations, Ca2+ handling alterations, structural abnormalities, and autonomic nervous system imbalance. Predisposing factors include structural heart disease such as valvular regurgitation resulting in chronic atrial stretch, although many horses show so-called 'lone AF' or idiopathic AF in which no underlying cardiac abnormalities can be detected using routine diagnostic techniques. These horses may have underlying ion channel dysfunction or undiagnosed myocardial (micro)structural alterations. Atrial fibrillation itself results in electrical, contractile and structural remodelling, fostering AF maintenance. Electrical remodelling leads to shortening of the atrial effective refractory period, promoting reentry. Contractile remodelling consists of decreased myocardial contractility, while structural remodelling includes the development of interstitial fibrosis and atrial enlargement. Reverse remodelling occurs after cardioversion to sinus rhythm, but full recovery may take weeks to months depending on duration of AF. The clinical signs of AF depend on the aerobic demands during exercise, ventricular rhythm response and presence of underlying cardiac disease. In horses with so-called 'lone AF', clinical signs are usually absent at rest but during exercise poor performance, exercise-induced pulmonary hemorrhage, respiratory distress, weakness or rarely collapse may develop.
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Affiliation(s)
- Annelies Decloedt
- Equine Cardioteam Gent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium.
| | - Glenn Van Steenkiste
- Equine Cardioteam Gent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium
| | - Lisse Vera
- Equine Cardioteam Gent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Gunther van Loon
- Equine Cardioteam Gent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium
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15
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Buhl R, Hesselkilde EM, Carstensen H, Fenner MF, Jespersen T, Tfelt-Hansen J, Michael Sattler S. Detection of atrial fibrillation with implantable loop recorders in horses. Equine Vet J 2020; 53:397-403. [PMID: 32506470 PMCID: PMC7891449 DOI: 10.1111/evj.13301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 04/16/2020] [Accepted: 05/18/2020] [Indexed: 11/28/2022]
Abstract
Background Cardiac arrhythmias in horses are diagnosed by auscultation or electrocardiogram (ECG), which results in a low sensitivity for detecting arrhythmias that occur sporadically. Implantable loop recorders (ILRs) are small ECG devices placed subcutaneously, to automatically detect arrhythmias in human patients. Objectives To test ILRs ability to detect atrial fibrillation (AF) in horses. Furthermore, we hypothesised that anatomical location of the implant site might influence signal quality. Signal quality was evaluated both during exercise and over time. Study design Experimental study. Methods In five Standardbred mares, eleven ILRs were implanted subcutaneously in up to three different positions (Front: pectoral region, Left‐6: sixth left intercostal space and Ventral: xiphoid region) and AF induced. The R‐ and T‐wave amplitudes were measured in all positions over time during AF. AF burden automatically registered by the ILRs over a 2‐month period was compared with selected Holter ECG recordings. Results All three positions had stable R‐ and T‐wave amplitudes during the study period and were of sufficient quality to allow AF detection at rest. The position Left‐6 showed significantly higher R‐ and T‐wave amplitudes compared with the other positions. During submaximal exercise only the Left‐6 position was able to record ECG signals of diagnostic quality. No position yielded diagnostic signals at maximum exercise due to artefacts. Main limitations Few horses and ILRs included and no spontaneous AF episodes were studied. Conclusions This preliminary study indicates that ILRs can be used for AF detection in horses, but the anatomical location is important for optimal ECG quality. Despite insufficient quality during exercise, ILRs were suitable for AF detection at rest. Therefore, the ILR may be a valuable diagnostic tool for detecting paroxysmal AF in horses.
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Affiliation(s)
- Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eva M Hesselkilde
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Helena Carstensen
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Merle F Fenner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Jespersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Tfelt-Hansen
- Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Copenhagen, Denmark.,Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stefan Michael Sattler
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Copenhagen, Denmark
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16
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Abstract
Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in humans and is a significant source of morbidity and mortality. Despite its prevalence, our mechanistic understanding is incomplete, the therapeutic options have limited efficacy, and are often fraught with risks. A better biological understanding of AF is needed to spearhead novel therapeutic avenues. Although "natural" AF is nearly nonexistent in most species, animal models have contributed significantly to our understanding of AF and some therapeutic options. However, the impediments of animal models are also apparent and stem largely from the differences in basic physiology as well as the complexities underlying human AF; these preclude the creation of a "perfect" animal model and have obviated the translation of animal findings. Herein, we review the vast array of AF models available, spanning the mouse heart (weighing 1/1000th of a human heart) to the horse heart (10× heavier than the human heart). We attempt to highlight the features of each model that bring value to our understanding of AF but also the shortcomings and pitfalls. Finally, we borrowed the concept of a SWOT analysis from the business community (which stands for strengths, weaknesses, opportunities, and threats) and applied this introspective type of analysis to animal models for AF. We identify unmet needs and stress that is in the context of rapidly advancing technologies, these present opportunities for the future use of animal models.
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Affiliation(s)
- Dominik Schüttler
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - Aneesh Bapat
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.).,Cardiac Arrhythmia Service, Division of Cardiology, Massachusetts General Hospital, Boston (A.B., W.J.H.)
| | - Stefan Kääb
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.)
| | - Kichang Lee
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.)
| | - Philipp Tomsits
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - Sebastian Clauss
- From the Department of Medicine I, University Hospital Munich, Campus Großhadern, Ludwig-Maximilians University Munich (LMU), Germany (D.S., S.K., P.T., S.C.).,DZHK (German Centre for Cardiovascular Research), Partner Site Munich, Munich Heart Alliance (MHA), Germany (D.S., S.K., P.T., S.C.).,Walter Brendel Centre of Experimental Medicine, Ludwig-Maximilians University Munich (LMU), Germany (D.S., P.T., S.C.)
| | - William J Hucker
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston (A.B., K.L., W.J.H.).,Cardiac Arrhythmia Service, Division of Cardiology, Massachusetts General Hospital, Boston (A.B., W.J.H.)
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17
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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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18
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The complexity of clinically-normal sinus-rhythm ECGs is decreased in equine athletes with a diagnosis of paroxysmal atrial fibrillation. Sci Rep 2020; 10:6822. [PMID: 32321950 PMCID: PMC7176685 DOI: 10.1038/s41598-020-63343-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 03/09/2020] [Indexed: 11/09/2022] Open
Abstract
Equine athletes have a pattern of exercise which is analogous to human athletes and the cardiovascular risks in both species are similar. Both species have a propensity for atrial fibrillation (AF), which is challenging to detect by ECG analysis when in paroxysmal form. We hypothesised that the proarrhythmic background present between fibrillation episodes in paroxysmal AF (PAF) might be detectable by complexity analysis of apparently normal sinus-rhythm ECGs. In this retrospective study ECG recordings were obtained during routine clinical work from 82 healthy horses and from 10 horses with a diagnosis of PAF. Artefact-free 60-second strips of normal sinus-rhythm ECGs were converted to binary strings using threshold crossing, beat detection and a novel feature detection parsing algorithm. Complexity of the resulting binary strings was calculated using Lempel-Ziv (‘76 & ‘78) and Titchener complexity estimators. Dependence of Lempel-Ziv ‘76 and Titchener T-complexity on the heart rate in ECG strips obtained at low heart rates (25–60 bpm) and processed by the feature detection method was found to be significantly different in control animals and those diagnosed with PAF. This allows identification of horses with PAF from sinus-rhythm ECGs with high accuracy.
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19
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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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20
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Boegli J, Schwarzwald CC, Mitchell KJ. Diagnostic value of noninvasive pulse pressure measurements in Warmblood horses with aortic regurgitation. J Vet Intern Med 2019; 33:1446-1455. [PMID: 30938891 PMCID: PMC6524107 DOI: 10.1111/jvim.15494] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 03/21/2019] [Indexed: 12/21/2022] Open
Abstract
Background Noninvasive blood pressures (NIBP) and pulse pressures (PP) have not been published in horses with aortic and mitral regurgitation (AR or MR). Objectives To investigate NIBP and PP in healthy Warmblood horses and horses with AR and MR and propose PP cutoffs to identify and stage AR severity. Animals Seventy‐three Warmblood horses (healthy, 10; AR, 31; MR, 32). Methods Retrospective study. All horses had NIBP and an echocardiogram recorded. Cases were categorized based on severity of regurgitation. Pulse pressures were compared among healthy, MR, and AR groups and among AR severity groups. Cutoffs were determined by receiver operating characteristic curve analyses. Results Horses with AR had higher PP than horses with MR (mean difference [95% confidence interval (CI)], +17 [9‐26] mm Hg, P < .001) and controls (+17 [5‐30] mm Hg; P =.004). Horses with severe AR had higher PP compared those with mild (+38 [20‐54] mm Hg; P < 0.001) and moderate AR (+33 [18‐47] mm Hg; P < .001). The PP cutoffs to distinguish AR from MR and controls were 38 mm Hg (sensitivity [Sn], 100%; specificity [Sp], 19%) for maximal Sn and 61 mm Hg (Sn, 43%; Sp, 100%) for maximal Sp. The PP cutoffs to distinguish severe AR from mild and moderate AR were 57 mm Hg (Sn, 100%; Sp, 70%) for maximal Sn and 77 mm Hg (Sn, 75%; Sp, 100%) for maximal Sp. Conclusions and Clinical Importance Horses with AR have increased PP. Noninvasive PP measurements interpreted with provided cutoffs may aid clinicians in diagnosing and staging severity of AR in horses.
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Affiliation(s)
- Julia Boegli
- Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Colin C Schwarzwald
- Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Katharyn J Mitchell
- Equine Department, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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21
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Abstract
Degenerative myxomatous disease is common and is associated with aging. Poor prognostic indicators for equine aortic regurgitation specifically include ventricular ectopy, increased pulse pressure, and hyperkinetic pulses. Valvular prolapse is a functional abnormality diagnosed echocardiographically, about which knowledge is limited. A better understanding of its role in valvular regurgitation is needed. Infective endocarditis presents with fever and other systemic signs accompanying valvular regurgitation. The prognosis is poor, warranting aggressive therapy. Other forms of valvular disease occur rarely, but often presenting with severe regurgitation. Management of horses with valvular disease is focused on assessment of severity and regular clinical, echocardiographic, and electrocardiographic monitoring.
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22
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Abstract
Congenital heart disease (CHD) represents a small proportion of horses undergoing clinical evaluation; however, both simple and complex defects occur during cardiac development leading to many unique malformations. This article reviews cardiac development and the fetal circulation, describes the morphologic method and the sequential segmental approach to CHD analysis, presents a summary of CHD in horses, and offers an overview of lesions that should be considered during evaluation of horses suspected to have CHD. For many forms of equine CHD, therapies are limited because cardiac interventions and cardiac surgery are not routinely pursued in this species.
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Affiliation(s)
- Brian A Scansen
- Department of Clinical Sciences, Colorado State University, Campus Delivery 1678, Fort Collins, CO 80523, USA.
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23
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Zuber N, Zuber M, Schwarzwald CC. Assessment of systolic and diastolic function in clinically healthy horses using ambulatory acoustic cardiography. Equine Vet J 2018; 51:391-400. [DOI: 10.1111/evj.13014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 08/21/2018] [Indexed: 12/13/2022]
Affiliation(s)
- N. Zuber
- Clinic for Equine Internal Medicine, Vetsuisse Faculty University of Zurich Zurich Switzerland
| | - M. Zuber
- Division of Cardiology University of Zurich Zurich Switzerland
| | - C. C. Schwarzwald
- Clinic for Equine Internal Medicine, Vetsuisse Faculty University of Zurich Zurich Switzerland
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24
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Hargreaves L, Gosling L, Dixon JJ. Pericardial effusion and congestive heart failure in a horse with multicentric lymphoma. VETERINARY RECORD CASE REPORTS 2018. [DOI: 10.1136/vetreccr-2018-000631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
A 20-year-old Warmblood mare was evaluated for acute-onset tachycardia and a one-week history of lethargy and ventral oedema. Haematology revealed leucocytosis with neutrophilia. Ultrasonographic examination revealed pericardial effusion and cardiac tamponade consistent with right-sided congestive heart failure. Abdominal ultrasonography demonstrated loss of definition of the right kidney and a structure adjacent to the kidney suggestive of a renal neoplasm. A tentative antemortem diagnosis of multicentric neoplasia, most likely lymphoma, was made. The horse was subjected to euthanasia due to a grave prognosis. Postmortem examination and histological evaluation were consistent with lymphoma, including infiltration of the cardiac muscle with neoplastic cells. Although lymphoma has been reported to affect the heart, congestive heart failure due to cardiac and pericardial neoplastic infiltration has not been previously reported as the presenting complaint. This case report describes the diagnostic approach to pericardial effusion and congestive heart failure in a mare with lymphoma.
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25
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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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26
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Broux B, De Clercq D, Decloedt A, Ven S, Vera L, van Steenkiste G, Mitchell K, Schwarzwald C, van Loon G. Heart rate variability parameters in horses distinguish atrial fibrillation from sinus rhythm before and after successful electrical cardioversion. Equine Vet J 2017; 49:723-728. [DOI: 10.1111/evj.12684] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/14/2017] [Indexed: 12/22/2022]
Affiliation(s)
- B. Broux
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - D. De Clercq
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - A. Decloedt
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - S. Ven
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - L. Vera
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - G. van Steenkiste
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
| | - K. Mitchell
- Equine Clinic; University of Zurich; Zurich Switzerland
| | | | - G. van Loon
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine; Ghent University; Merelbeke Belgium
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27
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Cerasoli I, Melis S, Loon G, De Clercq D, Brunsting J, Schauvliege S. Horse: anaesthetic management for open castration of a Belgian draught horse with interventricular septum defect, aortic regurgitation and ventricular premature depolarisations. VETERINARY RECORD CASE REPORTS 2017. [DOI: 10.1136/vetreccr-2016-000385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Ilaria Cerasoli
- Department of Surgery and AneasthesiologyGhent UniversityMerelbekeBelgium
| | - Sanne Melis
- Pride Veterinary CentreRiverside RdDerbyDE24 8HXUK
| | - Gunther Loon
- Department of Internal MedicineGhent UniversityMerelbekeBelgium
| | | | - Julie Brunsting
- Department of Surgery and AneasthesiologyGhent UniversityMerelbekeBelgium
| | - Stijn Schauvliege
- Department of Surgery and AneasthesiologyGhent UniversityMerelbekeBelgium
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Failure in Cardiac Action: Comparing Humans, Dogs, Cats, and Horses. Comp Med 2017. [DOI: 10.1007/978-3-319-47007-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
Respiratory and cardiac diseases are common in older horses. Advancing age is a specific risk factor for cardiac murmurs and these are more likely in males and small horses. Airway inflammation is the most common respiratory diagnosis. Recurrent airway obstruction can lead to irreversible structural change and bronchiectasis; with chronic hypoxia, right heart dysfunction and failure can develop. Valvular heart disease most often affects the aortic and/or the mitral valve. Management of comorbidity is an essential element of the therapeutic approach to cardiac and respiratory disease in older equids.
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Assessing aortic regurgitation severity from 2D, M-mode and pulsed wave Doppler echocardiographic measurements in horses. Vet J 2016; 210:34-8. [DOI: 10.1016/j.tvjl.2016.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 12/18/2015] [Accepted: 01/11/2016] [Indexed: 12/25/2022]
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31
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Topography and ultrasonographic identification of the equine pulmonary vein draining pattern. Vet J 2016; 210:17-23. [DOI: 10.1016/j.tvjl.2016.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 11/03/2015] [Accepted: 01/11/2016] [Indexed: 11/22/2022]
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Afonso T, Giguère S, Rapoport G, Barton MH, Coleman AE. Cardiovascular effects of pimobendan in healthy mature horses. Equine Vet J 2015; 48:352-6. [DOI: 10.1111/evj.12432] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/10/2015] [Indexed: 11/26/2022]
Affiliation(s)
- T. Afonso
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens USA
| | - S. Giguère
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens USA
| | - G. Rapoport
- Department of Small Animal Medicine and Surgery; College of Veterinary Medicine; University of Georgia; Athens USA
| | - M. H. Barton
- Department of Large Animal Medicine; College of Veterinary Medicine; University of Georgia; Athens USA
| | - A. E. Coleman
- Department of Small Animal Medicine and Surgery; College of Veterinary Medicine; University of Georgia; Athens USA
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Haugaard MM, Pehrson S, Carstensen H, Flethøj M, Hesselkilde EZ, Praestegaard KF, Diness JG, Grunnet M, Jespersen T, Buhl R. Antiarrhythmic and electrophysiologic effects of flecainide on acutely induced atrial fibrillation in healthy horses. J Vet Intern Med 2014; 29:339-47. [PMID: 25328012 PMCID: PMC4858114 DOI: 10.1111/jvim.12496] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 09/02/2014] [Accepted: 10/02/2014] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Only few pharmacologic compounds have been validated for treatment of atrial fibrillation (AF) in horses. Studies investigating the utility and safety of flecainide to treat AF in horses have produced conflicting results, and the antiarrhythmic mechanisms of flecainide are not fully understood. OBJECTIVES To study the potential of flecainide to terminate acutely induced AF of short duration (≥ 15 minutes), to examine flecainide-induced changes in AF duration and AF vulnerability, and to investigate the in vivo effects of flecainide on right atrial effective refractory period, AF cycle length, and ventricular depolarization and repolarization. ANIMALS Nine Standardbred horses. Eight received flecainide, 3 were used as time-matched controls, 2 of which also received flecainide. METHODS Prospective study. The antiarrhythmic and electrophysiologic effects of flecainide were based on 5 parameters: ability to terminate acute pacing-induced AF (≥ 15 minutes), and drug-induced changes in atrial effective refractory period, AF duration, AF vulnerability, and ventricular depolarization and repolarization times. Parameters were assessed at baseline and after flecainide by programmed electrical stimulation methods. RESULTS Flecainide terminated all acutely induced AF episodes (n = 7); (AF duration, 21 ± 5 minutes) and significantly decreased the AF duration, but neither altered atrial effective refractory period nor AF vulnerability significantly. Ventricular repolarization time was prolonged between 8 and 20 minutes after initiation of flecainide infusion, but no ventricular arrhythmias were detected. CONCLUSIONS AND CLINICAL IMPORTANCE Flecainide had clear antiarrhythmic properties in terminating acute pacing-induced AF, but showed no protective properties against immediate reinduction of AF. Flecainide caused temporary prolongation in the ventricular repolarization, which may be a proarrhythmic effect.
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Affiliation(s)
- M M Haugaard
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Taastrup, Denmark
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Hesselkilde EZ, Almind ME, Petersen J, Flethøj M, Præstegaard KF, Buhl R. Cardiac arrhythmias and electrolyte disturbances in colic horses. Acta Vet Scand 2014; 56:58. [PMID: 25274423 PMCID: PMC4189753 DOI: 10.1186/s13028-014-0058-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/29/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite increased focus on cardiac arrhythmias in horses, the nature and prevalence is still poorly described. Case reports suggest that arrhythmias occurring secondary to systemic disease are seen more commonly in the clinic than arrhythmias caused by cardiac disease. The aim of this study was to investigate the prevalence of arrhythmias in colic horses referred for hospital treatment. Associations between electrolyte disturbances and arrhythmias were also investigated. RESULTS Heart rate was 37.4 ± 3.7 bpm in the control group, and 51.6 ± 11.8 bpm, in the colic group, which was significantly different (P < 0.0001). AV blocks and SVPCs were found in both groups, however only colic horses showed VPCs. No significant difference between the two groups was found for AV blocks, SVPCs, and VPCs (P = 0.08 - 0.76). The mean levels of potassium, sodium, ionized calcium, and chloride were significantly lower in the colic group compared to the control group at admission. Mean levels of glucose and L-lactate were significantly elevated in the colic group (P < 0.05). CONCLUSIONS This study describes prevalence of cardiac arrhythmias and electrolytes concentrations in colic horses compared to healthy controls. Although we only observed VPCs in the colic horses, no significant differences between colic horses and controls were found. Despite the colic horses having electrolyte changes at admission no correlation was found between the electrolyte disturbances and cardiac arrhythmias. Although no clear conclusions can be drawn from the present study, the results indicate that relatively mild colic per se is not pro-arrhythmogenic, whereas severe colic probably are more likely to result in ventricular arrhythmia.
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Atrial Natriuretic Peptide as an Indicator of the Severity of Valvular Regurgitation and Heart Failure in Horses. J Equine Vet Sci 2014. [DOI: 10.1016/j.jevs.2014.08.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Pharmacokinetics and pharmacodynamics of enalapril and its active metabolite, enalaprilat, at four different doses in healthy horses. Res Vet Sci 2014; 97:105-10. [PMID: 24972864 DOI: 10.1016/j.rvsc.2014.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 05/02/2014] [Accepted: 06/08/2014] [Indexed: 11/23/2022]
Abstract
Pharmacokinetic and pharmacodynamic of IV enalapril at 0.50 mg/kg, PO placebo and PO enalapril at three different doses (0.50, 1.00 and 2.00 mg/kg) were analyzed in 7 healthy horses. Serum concentrations of enalapril and enalaprilat were determined for pharmacokinetic analysis. Angiotensin-converting enzyme (ACE) activity, serum ureic nitrogen (SUN), creatinine and electrolytes were measured, and blood pressure was monitored for pharmacodynamic analysis. The elimination half-lives of enalapril and enalaprilat were 0.67 and 2.76 h respectively after IV enalapril. Enalapril concentrations after PO administrations were below the limit of quantification (10 ng/ml) in all horses and enalaprilat concentrations were below the limit of quantification in 4 of the 7 horses. Maximum mean ACE inhibitions from baseline were 88.38, 3.24, 21.69, 26.11 and 30.19% for IV enalapril at 0.50 mg/kg, placebo and PO enalapril at 0.50, 1.00 and 2.00 mg/kg, respectively. Blood pressures, SUN, creatinine and electrolytes remained unchanged during the experiments.
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