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Kovacs S, Racz B, Sotonyi P, Bakos Z. Morphological and histological investigation of the conduction system in the equine atrial muscle sleeve of pulmonary veins. Equine Vet J 2024; 56:1059-1067. [PMID: 37658818 DOI: 10.1111/evj.13996] [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: 03/06/2023] [Accepted: 08/19/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND Atrial fibrillation is the most common arrhythmia in horses causing poor performance. The role of pulmonary vein triggers in the pathogenesis has been identified in horses. Ablation methods have been investigated, but the available information on anatomical, histological and immunohistochemical assessment of the pulmonary vein ostia and the conduction system of the myocardial sleeve is still limited. OBJECTIVES The aim of the study was to describe the morphological properties of the myocardial sleeve in healthy horses. STUDY DESIGN Cross-sectional. METHODS Eighty-three equine hearts were dissected. The number and diameters of pulmonary vein ostia were determined, and anatomical localisation was described. Fifty-eight tissue samples were collected for routine histology and 12 of these were used for immunohistochemistry (connexin 43, 45, S100, and tyrosine hydroxylase antibodies). RESULTS The mean number of pulmonary vein ostia was 4.5 (4 veins: 46 horse, 5 veins: 31 horses, 6 veins: 6 horses). Diameters (mean ± SD) of the main ostia were as follows: vein I: 20.2 ± 7.0 mm, vein II: 32.7 ± 7.1 mm, vein III: 33.4 ± 5.9 mm, vein IV: 18.1 ± 4.5 mm. Diameters of supernumerary vein ostia varied between 3.0 and 28.0 mm (11.5 ± 5.5 mm). Early branching was found in 26 horses (31.3%) and 30 veins (vein I: 14, vein II: 9, vein III: 5, vein IV: 2). Histology confirmed the presence of a muscle sleeve composed of myocardial tissue in each pulmonary vein. S100 and TH positivity was detected in each vein, and it confirmed the presence of adrenergic and non-adrenergic nerve fibres within the myocardial sleeve. Cx43 and 45 positivity were also found in each vein indicating the presence of gap junctions. MAIN LIMITATIONS The effect of bodyweight on pulmonary vein dimensions is unknown. CONCLUSIONS Future ablation techniques should consider that conductive tissue is present in the entire myocardial sleeve in all pulmonary vein ostia.
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Affiliation(s)
- Szilvia Kovacs
- Department and Clinic of Equine Medicine, University of Veterinary Medicine, Budapest, Hungary
| | - Bence Racz
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Peter Sotonyi
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Zoltan Bakos
- Department and Clinic of Equine Medicine, University of Veterinary Medicine, Budapest, Hungary
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Vernemmen I, Buschmann E, Demeyere M, Verhaeghe LM, Van Steenkiste G, Decloedt A, van Loon G. Feasibility of transthoracic echocardiographic guidance for multicatheter electrophysiological mapping studies in horses. J Vet Intern Med 2024. [PMID: 39096119 DOI: 10.1111/jvim.17156] [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: 03/04/2024] [Accepted: 07/18/2024] [Indexed: 08/04/2024] Open
Abstract
BACKGROUND Improved characterization of arrhythmias is based on minimally invasive catheterizations. However, these catheterizations have been poorly explored in horses because apart from 3-dimensional (3D) mapping systems, continuous guidance of the catheter's position with adequate detail is difficult using current imaging modalities. HYPOTHESIS Position multiple electrophysiology catheters simultaneously at predetermined strategical positions in the heart using transthoracic echocardiographic guidance. ANIMALS Eight adult healthy horses. METHODS Observational study. Two electrophysiological studies were performed: 1 procedure with catheters positioned in the right heart in the standing sedated horse and 1 procedure under general anesthesia with catheters positioned in the left heart. Except for the coronary sinus catheter, each catheter positioning was simultaneously guided by right-parasternal transthoracic echocardiography and 3D electro-anatomical mapping. RESULTS For each catheter position, a central imaging plane was taken as the starting point, after which the imaging probe was shifted, rotated, and angulated to visualize the catheter over its entire length, including its distal electrode. Catheter positionings in the right heart and left ventricle were successfully guided in the majority of the horses whereas catheter positionings in the left atrium, and especially the pulmonary veins, were challenging to guide echocardiographically. CONCLUSIONS AND CLINICAL IMPORTANCE Ultrasound guidance of catheters to specific positions useful for electrophysiological mapping was feasible in the right heart and left ventricle but challenging for the left atrium. This approach creates a perspective for minimally invasive arrhythmia diagnosis without the need for a 3D mapping system. Left parasternal views and intracardiac echocardiography might provide better guidance for left atrial positions.
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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
| | - Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Marie Demeyere
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Lize-Maria Verhaeghe
- 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
| | - 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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Dufourni A, Buschmann E, Vernemmen I, Van Steenkiste G, van Loon G, Decloedt A. Effect of physiological and pharmacological stress on heart rate, blood pressure, and echocardiographic measurements in healthy Warmblood horses. J Vet Intern Med 2024; 38:398-410. [PMID: 38174810 PMCID: PMC10800213 DOI: 10.1111/jvim.16967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 11/20/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Echocardiographic measurements are important prognostic indicators but might be influenced by heart rate and blood pressure. This is particularly important when comparing repeated examinations. HYPOTHESIS To determine the effect of physiological stress at mildly increased heart rates and pharmacological challenge using IV administration of N-butylscopolammonium bromide and metamizol sodium on heart rate, blood pressure, and echocardiographic measurements. ANIMALS Twenty healthy Warmblood horses. METHODS Randomized crossover study. Horses were examined echocardiographically by 2-dimensional, M-mode, pulsed wave (PW) Doppler, and PW tissue Doppler imaging with simultaneous ECG recording and noninvasive blood pressure measurements during rest, physiological stress, and pharmacological challenge. Cardiac dimensions and functions were measured by a blinded observer. Data were analyzed using repeated-measures analysis of variance. RESULTS Mean heart rate and arterial blood pressure were significantly higher during physiological stress (46 ± 2 bpm, 93 ± 16 mm Hg) and pharmacological challenge (62 ± 13 bpm, 107 ± 17 mm Hg) compared with rest (34 ± 3 bpm, 86 ± 12 mm Hg; P < .05). Compared with rest, physiological stress resulted in increased left atrial fractional area change (34.3 ± 7.5 vs 27.3 ± 5.1%; P = .01) and left ventricular late diastolic radial wall motion velocity (13 ± 3 vs 10 ± 2 cm/s; P = .01) but had no significant effect on most other echocardiographic variables. Compared with rest, pharmacological challenge led to significantly decreased left atrial and diastolic ventricular dimensions (left ventricular internal diameter: 10.3 ± 0.9 vs 10.7 ± 0.8 cm; P = .01), increased aortic and pulmonary diameters, and ventricular wall thickness. CONCLUSIONS AND CLINICAL IMPORTANCE Physiological stress at mildly increased heart rates significantly enhanced atrial pump function. Larger heart rate and blood pressure increases during pharmacological challenge resulted in altered cardiac dimensions. This should be taken into account when evaluating echocardiographic measurements at increased heart rates.
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Affiliation(s)
- Alexander Dufourni
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Eva Buschmann
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Ingrid Vernemmen
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Gunther van Loon
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent University, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
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Vernemmen I, Van Steenkiste G, Hauspie S, De Lange L, Buschmann E, Schauvliege S, Van den Broeck W, Decloedt A, Vanderperren K, van Loon G. Development of a three-dimensional computer model of the equine heart using a polyurethane casting technique and in vivo contrast-enhanced computed tomography. J Vet Cardiol 2023; 51:72-85. [PMID: 38101318 DOI: 10.1016/j.jvc.2023.11.014] [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: 12/30/2022] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 12/17/2023]
Abstract
INTRODUCTION/OBJECTIVES Insight into the three-dimensional (3D) anatomy of the equine heart is essential in veterinary education and to develop minimally invasive intracardiac procedures. The aim was to create a 3D computer model simulating the in vivo anatomy of the adult equine heart. ANIMALS Ten horses and five ponies. MATERIALS AND METHODS Ten horses, euthanized for non-cardiovascular reasons, were used for in situ cardiac casting with polyurethane foam and subsequent computed tomography (CT) of the excised heart. In five anaesthetized ponies, a contrast-enhanced electrocardiogram-gated CT protocol was optimized to image the entire heart. Dedicated image processing software was used to create 3D models of all CT scans derived from both methods. Resulting models were compared regarding relative proportions, detail and ease of segmentation. RESULTS The casting protocol produced high detail, but compliant structures such as the pulmonary trunk were disproportionally expanded by the foam. Optimization of the contrast-enhanced CT protocol, especially adding a delayed phase for visualization of the cardiac veins, resulted in sufficiently detailed CT images to create an anatomically correct 3D model of the pony heart. Rescaling was needed to obtain a horse-sized model. CONCLUSIONS Three-dimensional computer models based on contrast-enhanced CT images appeared superior to those based on casted hearts to represent the in vivo situation and are preferred to obtain an anatomically correct heart model useful for education, client communication and research purposes. Scaling was, however, necessary to obtain an approximation of an adult horse heart as cardiac CT imaging is restricted by thoracic size.
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Affiliation(s)
- I Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
| | - G Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - S Hauspie
- Department of Morphology, Imaging, Orthopaedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - L De Lange
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - E Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - S Schauvliege
- Department of Large Animal Surgery, Anaesthesia and Orthopaedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - W Van den Broeck
- Department of Morphology, Imaging, Orthopaedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - A Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - K Vanderperren
- Department of Morphology, Imaging, Orthopaedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - G van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Echocardiographic Features of the Ductus Arteriosus and the Foramen Ovale in a Hospital-Based Population of Neonatal Foals. Animals (Basel) 2022; 12:ani12172242. [PMID: 36077962 PMCID: PMC9454784 DOI: 10.3390/ani12172242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/21/2022] [Accepted: 08/26/2022] [Indexed: 11/28/2022] Open
Abstract
Simple Summary In fetal circulation, the distribution of oxygenated blood from the maternal placenta is facilitated by two intracardiac shunts. Oxygenated blood flows from the right atrium to the left heart through the foramen ovale, which is formed by the septum primum and septum secundum. Less oxygenated blood is directed to the placenta through the ductus arteriosus, which connects the pulmonary artery and the aorta. The ductus arteriosus and foramen ovale should close after birth. However, knowledge about the exact time of closure of those structures in foals is limited. The current study investigates the ultrasonographical closure of both the ductus arteriosus and the foramen ovale in healthy and diseased neonatal foals. Cardiac auscultation and ultrasound were performed on fifty foals. Cardiac murmurs were common, and in some foals, the ductus arteriosus was still open at ten days of age. The foramen ovale was not open; however, a fluttering motion of the septum primum into the left atrium was a common finding in healthy and diseased foals. The exact clinical importance of those findings needs to be further elucidated. Abstract The ductus arteriosus (DA) and foramen ovale (FO), including the septum primum (SP) and septum secundum (SS), are important structures in fetal circulation and are unexplored in neonatal equids. The objective of this study is to describe echocardiographic characteristics in a hospital-based population of neonatal foals. On days 2, 5 and 10 after parturition, cardiac ultrasound was performed, and clinical data were collected in healthy and diseased Warmblood foals. Fifty healthy (n = 15) and diseased (n = 35) Warmblood foals were examined. A left-sided and right-sided holosystolic murmur was audible in 98% (n = 42) and 51% (n = 22), respectively, on day 2; in 81% (n = 25) and 19% (n = 6) on day 5; and in 44% (n = 4) and 11% (n = 1) on day 10. The median grade of the systolic murmurs was higher when the DA was open. Flow through the DA could be visualized with color flow and continuous wave (CW) Doppler from the left parasternal long-axis view of the pulmonary artery in 40/43 foals on day 2, 9/31 foals on day 5 and 2/9 foals on day 10. The DA diameter was 2 ± 1 mm on day 2, 2 ± 1 mm on day 5 and 1 mm on day 10. The thickness of both septa of the FO was similar. The SP fluttered into the left atrium at all ages, but the maximal distance between the SP and SS decreased over time. In conclusion, cardiac murmurs, a patent DA and fluttering FO are frequent findings in neonatal foals. While these findings are probably physiological, the clinical importance needs to be further elucidated.
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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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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] [MESH Headings] [Grants] [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 MedicineGhent UniversityMerelbekeBelgium
| | - Lisse Vera
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Annelies Decloedt
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Glenn Van Steenkiste
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Ingrid Vernemmen
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Gunther van Loon
- Equine Cardioteam, Department of Large Animal Internal Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
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Vernemmen I, Vera L, Van Steenkiste G, Deserranno B, Muylle S, Decloedt A, van Loon G. Right atrial-related structures in horses of interest during electrophysiological studies. Equine Vet J 2020; 53:1210-1217. [PMID: 33368591 DOI: 10.1111/evj.13413] [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: 08/03/2020] [Revised: 11/16/2020] [Accepted: 12/17/2020] [Indexed: 01/02/2023]
Abstract
BACKGROUND Arrhythmias are common in horses, but catheter-based minimally invasive electrophysiological studies and therapeutic interventions have been poorly explored in equine medicine, partly due to the lack of detailed anatomical knowledge of the equine heart. OBJECTIVES To describe the dimensions and anatomical features of some electrophysiologically important landmarks of the right atrium in detail and assess their correlation with bodyweight and aortic diameter. STUDY DESIGN Ex vivo cadaveric study. METHODS Twenty-one hearts of Warmblood horses, subjected to euthanasia for noncardiovascular reasons, were examined post-mortem. The dimensions and anatomical features of the coronary sinus, the great cardiac vein and the oval fossa were recorded. Spearman's Rho correlation coefficients were calculated for correlations between the quantitative parameters and bodyweight and aortic diameter. RESULTS Median dimensions for coronary sinus, great cardiac vein and oval fossa were obtained. A Thebesian valve, partially covering the ostium of the coronary sinus, was present in 9 of the 21 hearts. A median of 6.5 (range 4-9) valves were present in the great cardiac vein. Several parameters, among which the dimensions of the oval fossa and the length of the great cardiac vein, were significantly positively correlated with bodyweight and aortic diameter. MAIN LIMITATIONS Measurements do not consider the dynamic changes during the cardiac cycle as measurements were performed ex vivo. All specimens were retrieved from Warmblood horses, therefore measurements might not apply to other breeds. CONCLUSIONS This study delivers a detailed description of important right atrial-related structures, necessary for the development of minimally invasive intracardiac procedures in horses. Adequate imaging techniques will have to be explored in order to guide these procedures.
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Affiliation(s)
- Ingrid Vernemmen
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Lisse Vera
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Bram Deserranno
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Sofie Muylle
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gunther van Loon
- Equine Cardioteam Ghent University, Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Decloedt A, Van Steenkiste G, Vera L, Buhl R, van Loon G. Atrial fibrillation in horses Part 2: Diagnosis, treatment and prognosis. Vet J 2020; 268:105594. [PMID: 33468306 DOI: 10.1016/j.tvjl.2020.105594] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 10/27/2020] [Accepted: 12/10/2020] [Indexed: 10/22/2022]
Abstract
Atrial fibrillation (AF) is suspected by an irregularly irregular rhythm during auscultation at rest and should be confirmed by electrocardiography. Heart rate monitoring is potentially interesting for AF detection by horse owners, based on the disproportionally high heart rate during exercise or increased heart rate variability. Echocardiography and laboratory analysis are useful to identify underlying cardiac disease. Horses with severe cardiac disease should not undergo cardioversion due to the risk of recurrence. Cardioversion is recommended especially in horses performing high intensity exercise or showing average maximal heart rates higher than 220 beats per min or abnormal ventricular complexes during exercise or stress. Pharmacological cardioversion can be performed using quinidine sulphate administered orally, with an overall mean reported success rate around 80%. Other therapeutic drugs have been described such as flecainide, amiodarone or novel atrial specific compounds. Transvenous electrical cardioversion (TVEC) is performed by delivering a shock between two cardioversion catheters positioned in the left pulmonary artery and right atrium, with a success rate of >95%. After cardioversion, most horses return to their previous level of performance. However, the recurrence rate after pharmacological or electrical cardioversion is up to 39%. Recurrence has been related to previous unsuccessful treatment attempts, valvular regurgitation and the presence of atrial premature depolarisations or low atrial contractile function after cardioversion. Large atrial size and long AF duration have also been suggested as risk factors. Different approaches for preventing recurrence have been described such as the administration of sotalol, however, large clinical studies have not been published.
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Affiliation(s)
- Annelies Decloedt
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium.
| | - Glenn Van Steenkiste
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium
| | - Lisse Vera
- 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
- Department of Large Animal Internal Medicine, Faculty of Veterinary Medicine, Ghent University, Belgium
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Worsman FCF, Miller ZJ, Shaw DJ, Blissitt KJ, Keen JA. Real-time three-dimensional echocardiography for left atrial volume assessment in Thoroughbred racehorses: Observer variability and comparison with two-dimensional echocardiography. Equine Vet J 2020; 54:176-190. [PMID: 33345356 DOI: 10.1111/evj.13408] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/13/2020] [Accepted: 12/03/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Left atrial size predicts cardiac morbidity and mortality in humans and dogs. Real-time three-dimensional echocardiography (3DE) may be reliable for assessing left atrial volume (LAV) in horses. OBJECTIVES To determine intra- and interobserver variability estimates of 3DE-LAV and compare it to that of 2DE-LAV estimates. STUDY DESIGN Method comparison. METHODS 3DE datasets were obtained from 40 horses, then graded for quality, creating a final study population of 22 horses. The 3DE and 2DE maximum LAV (LAVmax ) and minimum LAV (LAVmin ) were measured, and left atrial emptying volume (LA EV) and left atrial ejection fraction (LA EF) were calculated, from the same 3D dataset on four occasions using (a) a semi-automatic surface recognition algorithm and (b) a modified Simpson's method of discs. 3DE LAV measurements were repeated by a second observer. RESULTS For 3DE, median LAVmax was 596cm3 for observer one, and 852 cm3 for observer two, LAVmin was 373 cm3 for observer one and 533 cm3 for observer two. Low intraobserver measurement variation was observed for LAVmax and LAVmin , with horse-level intraclass correlation coefficients (ICChorse ) for both observers between 76% and 85% (horse added as random effect). The interobserver ICC was 58% for LAVmax and 50% for LAVmin on averaged measurements (with observer added as random effect), indicating consistent differences between observers. While intraobserver variation was similar for 2DE LAVmax measurements, it was greater for LAVmin (ICChorse = 67%). The intermethod ICC for 3DE vs 2DE was low at 14% for LAVmax and ~0% for LAVmin , indicating less-consistent differences with method. MAIN LIMITATIONS Small study population, low observer number, use of different imaging modalities (fundamental frequency and octave harmonics). CONCLUSIONS 3DE assessment of LAV was reliable, suggesting suitability for longitudinal evaluation of clinical cases. Clinicians should be aware of differences in LAV measurements between observers. More defined measurement guidelines may improve repeatability.
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Affiliation(s)
- Francesca C F Worsman
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, UK
| | - Zack J Miller
- Companion Care Vets Gloucester, Gloucester, Gloucestershire, UK
| | - Darren J Shaw
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, UK
| | - Karen J Blissitt
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, UK
| | - John A Keen
- The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Roslin, Midlothian, UK
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11
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Catheter-based electrical interventions to study, diagnose and treat arrhythmias in horses: From refractory period to electro-anatomical mapping. Vet J 2020; 263:105519. [PMID: 32928488 DOI: 10.1016/j.tvjl.2020.105519] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/03/2020] [Accepted: 07/14/2020] [Indexed: 11/23/2022]
Abstract
Minimally-invasive catheter-based interventional cardiology is a mainstay for the diagnosis and treatment of arrhythmias in human medicine. Very accurate imaging using fluoroscopy, CT and MRI is essential during interventional cardiology procedures. Because these imaging techniques are either not possible or provide too little anatomical detail in horses, echocardiography is currently the best technique to visualize catheters in horses. Over the past decades, catheter-based techniques have been applied to induce arrhythmias using pacing and to perform arrhythmia research using electrophysiological studies. In bradycardic animals with clinical signs, permanent pacing can be achieved by pacemaker implantation via the cephalic vein. Transvenous electrical cardioversion, based on one cardioversion catheter in the pulmonary artery and one in the right atrium, has become the treatment of choice for atrial fibrillation in horses, even for longstanding or drug-resistant atrial fibrillation. Recently, the highly advanced technique of three dimensional electroanatomical mapping has been described in horses. This technique has not only revealed essential electrophysiological data in horses, but has also facilitated the successful ablation of atrial tachycardia in horses.
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12
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Hesselkilde E, Linz D, Saljic A, Carstensen H, Kutieleh R, Jespersen T, Sanders P, Buhl R. First catheter-based high-density endocardial 3D electroanatomical mapping of the right atrium in standing horses. Equine Vet J 2020; 53:186-193. [PMID: 32285961 PMCID: PMC7818172 DOI: 10.1111/evj.13265] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 03/24/2020] [Accepted: 04/04/2020] [Indexed: 01/03/2023]
Abstract
Background Three‐dimensional electroanatomical mapping is of potential interest in equine cardiology to identify arrhythmia mechanisms, characterise electroanatomical substrates and guide ablation strategies. Objectives To describe three‐dimensional electroanatomical mapping in standing horses. Study design Research methodology, proof of concept study. Methods Four Standardbred horses (2 geldings, 2 mares, median age 4.5 [4‐9] years, mean bodyweight 485 [440‐550] kg) were sedated and placed in stocks. Via the jugular vein, a high‐density multipolar grid catheter (Advisor™ HD Grid Mapping Catheter with EnSite VelocityTM, Abbott Medical) was used for endocardial mapping of the right atrium. The P‐wave on the surface ECG was used as a timing reference for simultaneous local activation time‐ and bipolar voltage‐mapping. For a positional reference a 10‐pole catheter (Abbott Medical) was placed in the caudal vena cava. Results Endocardial right atrial mapping guided by the three‐dimensional mapping system and local electrograms was successfully performed in all four horses. A median of 32719 [25499‐65078] points, covering the entire right atrium, were collected. Three‐dimensional electroanatomical mapping provided detailed information about activation patterns and electrogram‐characteristics of the sinoatrial node, intervenous tubercle and cavotricuspid isthmus. Additionally, transvenous biopsy forceps connected to the mapping system were visualised on screen to guide biopsy collection. Main limitations The feasibility of electroanatomical mapping for the left atrium and in larger breeds requires further study. Conclusions High‐density three‐dimensional electroanatomical mapping of the right atrium is feasible in the standing horse.
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Affiliation(s)
- Eva Hesselkilde
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Dominik Linz
- Centre for Heart Rhythm Disorders, Royal Adelaide Hospital, University of Adelaide, Adelaide, Australia
| | - Arnela Saljic
- Department of Biomedical 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
| | | | - Thomas Jespersen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Prashanthan Sanders
- Centre for Heart Rhythm Disorders, Royal Adelaide Hospital, University of Adelaide, Adelaide, Australia
| | - Rikke Buhl
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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13
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Panopoulos I, Auriemma E, Specchi S, Diana A, Pietra M, Papastefanou A, Zini E, Cipone M. 64-multidetector CT anatomical assessment of the feline bronchial and pulmonary vascular structures. J Feline Med Surg 2019; 21:893-901. [PMID: 30407139 PMCID: PMC11132249 DOI: 10.1177/1098612x18807778] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The aim of the study was to provide a detailed anatomical study of the feline bronchial and vascular structures by using CT angiography (CTA). METHODS Adult cats with no respiratory clinical signs were enrolled in a CTA protocol to provide an anatomical study of the thorax. The dimensions, number of branches and branching pattern (monopodial vs dichotomic) of both bronchial and pulmonary vascular structures were evaluated under positive inspiration apnoea. A linear generalised estimating equations analysis (Spearman's rho) was used to identify statistical correlation between tracheal diameter, age and body weight of the cats. RESULTS Fourteen cats met the inclusion criteria. The pulmonary arteries had larger diameters than the pulmonary veins, and the pulmonary veins had larger diameters than the bronchial structures. A higher number of segmental bronchial and pulmonary vascular branches was observed in the left caudal lung lobe than in the other lobes. The monopodial branching pattern of both bronchial and pulmonary vascular structures was predominant in all cats of our study (100%) in cranial, caudal and right middle lung lobes, while a dichotomic branching pattern of the bronchial and pulmonary vascular structures of the accessory lung lobe was seen in 13 cats (93%). Thirteen cats (93%) had three pulmonary vein ostia, and one cat (7%) also presented with an additional left intermediate pulmonary vein ostium. Variation in the number of segmental pulmonary vein branches was noted in the right caudal lung lobe. There was no statistical correlation between tracheal diameter, age and weight. CONCLUSIONS AND RELEVANCE Architecture of the feline bronchovascularr structures belongs to a mixed type of monopodial and dichotomic branching pattern. In cats, the pulmonary venous drainage system predominately presents three pulmonary vein ostia. Variations in the type of formation and the number of branches of the pulmonary venous drainage system were noted.
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Affiliation(s)
| | - Edoardo Auriemma
- Department of Diagnostic Imaging, Veterinary Institute of Novara, Novara, Italy
| | - Swan Specchi
- Department of Diagnostic Imaging, Veterinary Institute of Novara, Novara, Italy
| | - Alessia Diana
- Department of Veterinary Medical Sciences, University of Bologna, Italy
| | - Marco Pietra
- Department of Veterinary Medical Sciences, University of Bologna, Italy
| | | | - Eric Zini
- Clinic for Small Animal Internal Medicine, Zurich University, Vetsuisse-Faculty, Zurich, Switzerland
- Department of Animal Medicine, Production and Health, University of Padua, Legnaro, Italy
- Department of Internal Medicine, Istituto Veterinario di Novara, Novara, Italy
| | - Mario Cipone
- Department of Veterinary Medical Sciences, University of Bologna, Italy
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14
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Caivano D, Corda A, Rishniw M, Giorgi ME, Parpaglia MLP, Conti MB, Porciello F, Birettoni F. Transthoracic M-mode echocardiographic assessment of pulmonary vein-to-pulmonary artery ratio in healthy horses. PLoS One 2019; 14:e0221154. [PMID: 31412072 PMCID: PMC6693752 DOI: 10.1371/journal.pone.0221154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 07/31/2019] [Indexed: 11/18/2022] Open
Abstract
Equine cardiovascular structures and function are routinely assessed by transthoracic echocardiography. Recently, investigators have described the echocardiographic visualization of equine pulmonary vein ostia. In companion animals, the right pulmonary vein (RPV) to right pulmonary artery (RPA) ratio has been used as an index to estimate the severity of cardiac diseases resulting in left ventricular volume overload. We sought to assess the feasibility of measuring RPV and RPA dimensions, and sought to provide various previously examined RPV and RPA variables in clinically healthy horses that could be used to assess cardiopulmonary disease status. Echocardiographic examination was prospectively performed in 70 healthy horses. The RPV and RPA were visualized using a modified right parasternal long-axis view and maximum and minimum diameters of both vessels were measured from 2D guided M-mode traces. The aortic diameter (Ao) was measured from the right parasternal short-axis view in early diastole. These measurements were then used to produce various ratio indices. RPV and RPA were imaged in all 70 horses. Median of the minimum and maximum RPV/RPA was 0.51 and 0.60, respectively. Median fractional dimensional change of vessels was 33% for RPV and 22% for RPA. The medians of the minimum and maximum RPV/Ao and RPA/Ao were 0.18, 0.28, 0.35 and 0.46, respectively. No relationships between either bodyweight or heart rate and any of the vein or artery variables were identified (maximum r2 = 0.04). Inter- and intra-observer measurement variability was very good for all RPV and RPA measurements. Measuring of RPV and RPA diameters using M-mode transthoracic echocardiography is feasible in healthy horses. Further studies of these variables in horses with cardiac diseases are needed to determine the clinical applicability and utility.
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Affiliation(s)
- Domenico Caivano
- Department of Veterinary Medicine, University of Perugia, Perugia, Italy
| | - Andrea Corda
- Department of Veterinary Medicine, University of Sassari, Sassari, Italy
| | - Mark Rishniw
- Veterinary Information Network, Davis, California, United States of America
- Department of Clinical Sciences, Cornell University, Ithaca, New York, United States of America
| | - Maria Elena Giorgi
- Department of Veterinary Medicine, University of Perugia, Perugia, Italy
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15
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Cornillie P, Casteleyn C, von Horst C, Henry R. Corrosion casting in anatomy: Visualizing the architecture of hollow structures and surface details. Anat Histol Embryol 2019; 48:591-604. [PMID: 31120632 DOI: 10.1111/ahe.12450] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 12/31/2022]
Abstract
Corrosion casting is the technique by which a solid, negative replica is created from a hollow anatomical structure and liberated from its surrounding tissues. For centuries, different types of hardening substances have been developed to create such casts, but nowadays, thermosetting polymers are mostly used as casting medium. Although the principle and initial set-up are relatively easy, producing high-quality casts that serve their intended purpose can be quite challenging. This paper evaluates some of the more popular casting resins that are currently available and provides a step-by-step overview of the corrosion casting procedure, including surface casts of anatomical structures. Hurdles and pitfalls are discussed, along with possible solutions to circumvent them, based on personal experience by the authors.
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Affiliation(s)
- Pieter Cornillie
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Christophe Casteleyn
- Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | | | - Robert Henry
- College of Veterinary Medicine, Lincoln Memorial University, Harrogate, Tennessee
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16
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Pericardial Disease, Myocardial Disease, and Great Vessel Abnormalities in Horses. Vet Clin North Am Equine Pract 2019; 35:139-157. [PMID: 30871834 DOI: 10.1016/j.cveq.2018.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pericardial, myocardial, and great vessel diseases are relatively rare in horses. The clinical signs are often nonspecific and vague, or related to the underlying cause. Physical examination usually reveals tachycardia, fever, venous distension or jugular pulsation, a weak or bounding arterial pulse, ventral edema, and abnormal cardiac auscultation such as arrhythmia, murmur, or muffled heart sounds. The prognosis depends on the underlying cause and the disease progression, and ranges from full recovery to poor prognosis for survival. This article focuses on the etiology, diagnosis, prognosis, and treatment of pericarditis, pericardial mass lesions, myocarditis, cardiomyopathy, and great vessel aneurysm or rupture.
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Abstract
This article provides an overview on the principles of transthoracic echocardiography in horses. Indications for echocardiography, equipment, and technical considerations are discussed and a systematic approach for a complete echocardiographic examination in horses is described. Methods for assessment of chamber dimensions, allometric scaling of measurements, assessment of systolic and diastolic ventricular function, assessment of atrial function, hemodynamic assessment, and evaluation of valvular regurgitation are explained, focusing on traditional 2-dimensional (2D), motion-mode, and Doppler echocardiographic methods. Selected applications of newer echocardiographic methods, such as tissue Doppler imaging and 2D speckle tracking are also described.
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Affiliation(s)
- Colin C Schwarzwald
- Clinic for Equine Internal Medicine, Equine Department, Swiss Equine Cardiology Consulting, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, Zurich 8057, Switzerland.
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18
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Van Steenkiste G, De Clercq D, Vera L, Decloedt A, Loon G. Sustained atrial tachycardia in horses and treatment by transvenous electrical cardioversion. Equine Vet J 2019; 51:634-640. [DOI: 10.1111/evj.13073] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/06/2019] [Indexed: 01/10/2023]
Affiliation(s)
- G. Van Steenkiste
- Department of Large Animal Internal Medicine Ghent University Equine Cardioteam Ghent University Merelbeke Belgium
| | - D. De Clercq
- Department of Large Animal Internal Medicine Ghent University Equine Cardioteam Ghent University Merelbeke Belgium
| | - L. Vera
- Department of Large Animal Internal Medicine Ghent University Equine Cardioteam Ghent University Merelbeke Belgium
| | - A. Decloedt
- Department of Large Animal Internal Medicine Ghent University Equine Cardioteam Ghent University Merelbeke Belgium
| | - G. Loon
- Department of Large Animal Internal Medicine Ghent University Equine Cardioteam Ghent University Merelbeke Belgium
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19
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Pease A, Marr CM. How to publish diagnostic imaging studies: Common mistakes and recommendations. Equine Vet J 2018; 51:7-10. [DOI: 10.1111/evj.13037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Anthony Pease
- Equine Veterinary Journal; Fordham, Ely Cambridgeshire UK
| | - Celia M. Marr
- Equine Veterinary Journal; Fordham, Ely Cambridgeshire UK
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