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Buschmann E, Van Steenkiste G, Duytschaever M, Segers P, Ibrahim L, van Loon G, Decloedt A. In vitro characterization of radiofrequency ablation lesions in equine and swine myocardial tissue. Sci Rep 2024; 14:22877. [PMID: 39358479 PMCID: PMC11447003 DOI: 10.1038/s41598-024-74486-2] [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: 02/02/2024] [Accepted: 09/26/2024] [Indexed: 10/04/2024] Open
Abstract
Radiofrequency ablation is a promising technique for arrhythmia treatment in horses. Due to the thicker myocardial wall and higher blood flow in horses, it is unknown if conventional radiofrequency settings used in human medicine can be extrapolated to horses. The study aim is to describe the effect of ablation settings on lesion dimensions in equine myocardium. To study species dependent effects, results were compared to swine myocardium. Right ventricular and right and left atrial equine myocardium and right ventricular swine myocardium were suspended in a bath with circulating isotonic saline at 37 °C. The ablation catheter delivered radiofrequency energy at different-power-duration combinations with a contact force of 20 g. Lesion depth and width were measured and lesion volume was calculated. Higher power or longer duration of radiofrequency energy delivery increased lesion size significantly in the equine atrial myocardium and in equine and swine ventricular myocardium (P < 0.001). Mean lesion depth in equine atrial myocardium ranged from 2.9 to 5.5 mm with a diameter ranging from 6.9 to 10.1 mm. Lesion diameter was significantly larger in equine tissue compared to swine tissue (P = 0.020). Obtained data in combination with estimated wall thickness can improve lesion transmurality which might reduce arrhythmia recurrence. Optimal ablation settings may differ between species.
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Affiliation(s)
- Eva Buschmann
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium.
| | - Glenn Van Steenkiste
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
| | | | - Patrick Segers
- Institute of Biomedical Engineering and Technology, Faculty of Engineering and Architecture, Ghent University, Ghent, Belgium
| | - Lara Ibrahim
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Ghent University, Merelbeke, Belgium
| | - Gunther van Loon
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
| | - Annelies Decloedt
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Equine Cardioteam Ghent University, Ghent University, Merelbeke, Belgium
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Vernemmen I, Buschmann E, Van Steenkiste G, Demeyere M, Verhaeghe LM, De Somer F, Devreese KMJ, Schauvliege S, Decloedt A, van Loon G. Intracardiac ultrasound-guided transseptal puncture in horses: Outcome, follow-up, and perioperative anticoagulant treatment. J Vet Intern Med 2024; 38:2707-2717. [PMID: 39086137 PMCID: PMC11423474 DOI: 10.1111/jvim.17158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 07/18/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Cardiac catheterizations in horses are mainly performed in the right heart, as access to the left heart traditionally requires an arterial approach. Transseptal puncture (TSP) has been adapted for horses but data on follow-up and closure of the iatrogenic atrial septal defect (iASD) are lacking. HYPOTHESIS/OBJECTIVES To perform TSP and assess postoperative complications and iASD closure over a minimum of 4 weeks. ANIMALS Eleven healthy adult horses. METHODS Transseptal puncture was performed under general anesthesia. Serum cardiac troponin I concentrations were measured before and after puncture. Weekly, iASD closure was monitored using transthoracic and intracardiac echocardiography. Relationship between activated clotting time and anti-factor Xa activity during postoperative enoxaparin treatment was assessed in vitro and in vivo. RESULTS Transseptal puncture was successfully achieved in all horses within a median duration of 22 (range, 10-104) minutes. Balloon dilatation of the puncture site for sheath advancement was needed in 4 horses. Atrial arrhythmias occurred in 9/11 horses, including atrial premature depolarizations (N = 1), atrial tachycardia (N = 5), and fibrillation (N = 3). Serum cardiac troponin I concentrations increased after TSP, but remained under the reference value in 10/11 horses. Median time to iASD closure was 14 (1-35) days. Activated clotting time correlated with anti-factor Xa activity in vitro but not in vivo. CONCLUSIONS AND CLINICAL IMPORTANCE Transseptal puncture was successfully performed in all horses. The technique was safe and spontaneous iASD closure occurred in all horses. Clinical application of TSP will allow characterization and treatment of left-sided arrhythmias in horses.
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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
| | - Glenn Van Steenkiste
- 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
| | - Filip De Somer
- Department of Human Structure and Repair, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Katrien M J Devreese
- Coagulation Laboratory, Ghent University Hospital, Department of Diagnostic Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium
| | - Stijn Schauvliege
- Department of Large Animal Surgery, Anaesthesia and Orthopaedics, 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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Vernemmen I, Buschmann E, Demeyere M, Verhaeghe L, 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; 38:2686-2697. [PMID: 39096119 PMCID: PMC11423469 DOI: 10.1111/jvim.17156] [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: 03/04/2024] [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 MedicineGhent UniversityGhentBelgium
| | - Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
| | - Marie Demeyere
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
| | - Lize‐Maria Verhaeghe
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityGhentBelgium
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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: 1] [Impact Index Per Article: 1.0] [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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Buschmann E, Van Steenkiste G, Duytschaever M, Boussy T, Vernemmen I, Ibrahim L, Schauvliege S, Decloedt A, van Loon G. Successful caudal vena cava and pulmonary vein isolation in healthy horses using 3D electro-anatomical mapping and a contact force-guided ablation system. Equine Vet J 2024; 56:1068-1076. [PMID: 38151793 DOI: 10.1111/evj.14037] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/24/2023] [Indexed: 12/29/2023]
Abstract
BACKGROUND Recently, treatment of equine atrial tachycardia by three-dimensional electro-anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA) has been described. Myocardial sleeves in the caudal vena cava and pulmonary veins are a potential trigger for initiation and perpetuation of atrial tachycardia and atrial fibrillation in the horse. Isolation of these myocardial sleeves by RFCA may be an effective treatment for these arrhythmias. OBJECTIVES To describe the feasibility of 3D EAM and RFCA to isolate caudal vena cava and pulmonary veins in adult horses using 3D mapping and a contact force (CF)-guided ablation system. STUDY DESIGN In vivo experiments. METHODS 3D EAM and RFCA was performed in five horses without cardiovascular disease under general anaesthesia, using the CF-guided system CARTO®3. Point-by-point RFCA aimed for isolation of caudal vena cava and pulmonary veins. Radiofrequency energy was delivered in power-controlled mode with a target power of 45 W, CF between 10 and 15 g and 30 mL/min irrigation rate, until an ablation-index of 450-500 was reached. RESULTS In the right atrium, myocardial sleeves of the caudal vena cava were isolated (n = 5). In the left atrium, isolation of ostium II (n = 3), ostium III (n = 1) and ostium I, II and III en bloc (n = 1) was performed. Successful isolation was confirmed by entrance and exit block. MAIN LIMITATIONS Horses were euthanised at the end of the procedure, so long term effects such as potential reconnection of isolated veins could not be studied. CONCLUSIONS This is the first description of 3D EAM and RFCA with CARTO®3 in horses, thereby showing the technical feasibility and successful caudal vena cava and pulmonary vein isolation. CF measurement allowed monitoring of catheter-tissue contact, resulting in efficient acute lesion creation as confirmed by entrance and exit block. This is a promising treatment for cardiac arrhythmias in horses.
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Affiliation(s)
- Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | | | - Tim Boussy
- Department of Cardiology, AZ Groeninge, Kortrijk, Belgium
| | - Ingrid Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Lara Ibrahim
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Ghent University, Merelbeke, Belgium
| | - Stijn Schauvliege
- Department of Large Animal Surgery, Anaesthesia and Orthopaedics, Ghent University, Merelbeke, Belgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
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Paulussen E, Van Steenkiste G, Hermans BJM, Decloedt A, van Loon G, Delhaas T. Einthoven's triangle adapted for horses: Proposal for the Delta configuration. J Vet Intern Med 2024; 38:2698-2706. [PMID: 39193868 PMCID: PMC11423460 DOI: 10.1111/jvim.17179] [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: 03/25/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
BACKGROUND Reliable ECGs are crucial for diagnosing arrhythmias, yet a lack of standardization impedes arrhythmia diagnosis and treatment in horses. OBJECTIVES To objectively determine an optimal position of Einthoven's triangle for ECG recordings in horses at rest, which can form the basis for standardized ECG recording and improve diagnosis and treatment of arrhythmias. ANIMALS The study involved 72 healthy, warmblood horses aged between 3 and 20 years. METHODS In view of future 12-lead studies and vectorcardiography, requiring an orthogonal system, Einthoven's triangle was positioned around the heart, in the transverse plane. Therefore, 11 electrodes were placed encircling the thorax behind the olecranon, to construct triangles with a horizontal base. Electrocardiogram recordings from different triangles were analyzed. Signal processing involved filtering, R peak detection, and median complex generation. Principal component analysis (PCA) and Euclidean distance measures were employed for data analysis. RESULTS The left mid-thoracic and ventral regions had high PCA scores, indicating high information content. Base-down triangles exhibited higher summed Euclidean distances, contributing to enhanced diagnostic capabilities. A base-down triangle, called "Delta (Δ) configuration" emerged as most informative, while meeting all criteria. CONCLUSIONS AND CLINICAL IMPORTANCE The base-down "Delta configuration" is the optimal Einthoven's triangle adapted for horses, providing large amplitudes and potential to provide basic insights into the mechanisms and origins of cardiac arrhythmias. Because the Delta configuration is positioned in the transverse plane, it forms the ideal basis for 12-lead ECG recordings that provide vectorcardiograms in an orthogonal coordinate system. Standardizing electrode positioning could improve ECG data comparability in equine cardiology.
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Affiliation(s)
- Ellen Paulussen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Ben J. M. Hermans
- Department of Cardiology, Cardiovascular Research Institute Maastricht (CARIM)Maastricht University Medical CenterMaastrichtThe Netherlands
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Tammo Delhaas
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM)Maastricht UniversityMaastrichtThe Netherlands
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Nath LC, Saljic A, Buhl R, Elliott A, La Gerche A, Ye C, Schmidt Royal H, Lundgren Virklund K, Agbaedeng TA, Stent A, Franklin S. Histological evaluation of cardiac remodelling in equine athletes. Sci Rep 2024; 14:16709. [PMID: 39030282 PMCID: PMC11271503 DOI: 10.1038/s41598-024-67621-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 07/14/2024] [Indexed: 07/21/2024] Open
Abstract
Approximately 1-2 per 100,000 young athletes die from sudden cardiac death (SCD) and extreme exercise may be associated with myocardial scar and arrhythmias. Racehorses have a high prevalence of atrial fibrillation (AF) and SCD but the presence of myocardial scar and inflammation has not been evaluated. Cardiac tissues from the left (LAA) and right (RAA) atrial appendages, left ventricular anterior (LVAPM) and posterior (LVPPM) papillary muscles, and right side of the interventricular septum (IVS-R) were harvested from racehorses with sudden cardiac death (SCD, n = 16) or other fatal injuries (OFI, n = 17), constituting the athletic group (ATH, n = 33), and compared to sedentary horses (SED, n = 10). Horses in the ATH group had myocyte hypertrophy at all sites; increased fibrosis at all sites other than the LAA; increased fibroblast infiltration but a reduction in the overall extracellular matrix (ECM) volume in the RAA, LVAPM, and IVS-R compared to SED horses. In this horse model, athletic conditioning was associated with myocyte hypertrophy and a reduction in ECM. There was an excess of fibrocyte infiltration and focal fibrosis that was not present in non-athletic horses, raising the possibility of an exercise-induced pro-fibrotic substrate.
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Affiliation(s)
- L C Nath
- University of Adelaide, Adelaide, Australia.
| | - A Saljic
- University of Copenhagen, Copenhagen, Denmark
| | - R Buhl
- University of Copenhagen, Copenhagen, Denmark
| | - A Elliott
- University of Adelaide, Adelaide, Australia
| | - A La Gerche
- St Vincents Institute Medical Research, Fitzroy, Australia
| | - C Ye
- University of Copenhagen, Copenhagen, Denmark
| | | | | | | | - A Stent
- University of Melbourne, Parkville, Australia
| | - S Franklin
- University of Adelaide, Adelaide, Australia
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Vernemmen I, Van Steenkiste G, Buschmann E, Cornelis K, Schauvliege S, Ibrahim L, Decloedt A, van Loon G. Development of an atrial transseptal puncture procedure in horses to access the left heart: An ultrasound-guided jugular vein and transhepatic approach. Equine Vet J 2024. [PMID: 38522423 DOI: 10.1111/evj.14084] [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: 12/01/2023] [Accepted: 02/25/2024] [Indexed: 03/26/2024]
Abstract
BACKGROUND Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein. OBJECTIVES To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach. STUDY DESIGN In vivo experimental study. METHODS Transseptal puncture was performed in 18 horses admitted for euthanasia and donated for scientific research under general anaesthesia: using a jugular vein approach (10 horses), a transhepatic approach (2 horses) or both (6 horses). Radiofrequency energy was applied on a guidewire to perforate the FO and allow sheath advancement under intracardiac and transthoracic echocardiographic guidance. Puncture lesions were inspected post-mortem. RESULTS Transseptal puncture was successful in 17/18 horses, of which 15/16 jugular vein approaches and 5/8 transhepatic approaches. Failure was due to technical malfunction, inability to advance the guidewire toward the heart and inability to advance the sheath through the FO. Intracardiac echocardiography was essential to safely guide the puncture process. Atrial arrhythmias caused by the TSP occurred in 13/18 horses. Puncture lesions were found in the right atrium in the FO region, and left atrium ventral to pulmonary vein ostium III. MAIN LIMITATIONS Because in several horses two approaches were tested consecutively, it cannot be excluded that the second TSP was performed at the previous puncture site. Due to the developmental nature of the study the approaches were not randomised and did not allow comparison. CONCLUSION Transseptal puncture is feasible in horses using ultrasound guidance and allows for electrophysiological exploration of the left heart. Further studies are needed to evaluate post-operative follow-up.
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Affiliation(s)
- Ingrid Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Kristoff Cornelis
- Cardiology Department, Maria Middelares Heart Centre, Ghent, Belgium
| | - Stijn Schauvliege
- Department of Surgery and Anaesthesiology of Domestic Animals, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Lara Ibrahim
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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Ibrahim L, Buschmann E, van Loon G, Cornillie P. Morphological evidence of a potential arrhythmogenic substrate in the caudal and cranial vena cava in horses. Equine Vet J 2024. [PMID: 38391272 DOI: 10.1111/evj.14075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/05/2024] [Indexed: 02/24/2024]
Abstract
BACKGROUND Three-dimensional electro-anatomical mapping, previously performed in horses with atrial arrhythmias, has demonstrated the medial region of the caudal vena cava (CaVC), 1-8 cm caudal to the fossa ovalis, as an anatomical predilection site for atrial tachycardia associated with areas of slow conduction and conduction block. Slow conduction has also been recorded in the cranial vena cava (CrVC). OBJECTIVES To investigate the morphological characteristics of the myocardial sleeves (MS) in the CaVC and CrVC, in order to identify a potential substrate of right sided atrial arrhythmias. STUDY DESIGN Cross sectional. METHODS Post-mortem dissection of 37 hearts from adult warmblood horses without known cardiovascular disease. Macroscopic examination of the myocardial distribution, evaluated the MS area, length, width, and shape in the CaVC and the CrVC. At least 2 samples from each vena cava MS were histologically examined using Masson's trichrome staining. RESULTS Myocardial sleeves into the medial CaVC and into the CrVC were observed in all horses and showed variations in distribution, shape, and size between horses. Their mean ± standard deviation length from the limbus into the CaVC reached 5.7 ± 1.0 cm (maximum 8.3 cm), and from the azygos vein into the CrVC 5.3 ± 1.6 cm (maximum 8.6 cm). Myocardium-free islands were observed in the CaVC and CrVC in 30% and 6% of horses, respectively. Histologically, MS showed a non-uniform myocardial fibre arrangement, with presence of fibroadipose tissue, features known to result in slow conduction and pro-arrhythmia. MAIN LIMITATIONS Study only included horses without history of atrial arrhythmia. CONCLUSIONS Myocardial sleeves are present in both CaVC and CrVC, showing anatomical variations between horses. Tissue characteristics known to favour re-entry were identified indicating that these venae cavae MS are a potential substrate for atrial tachyarrhythmias and a target for treatment by ablation.
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Affiliation(s)
- Lara Ibrahim
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, 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
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Pieter Cornillie
- Department of Morphology, Imaging, Orthopedics, Rehabilitation and Nutrition, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
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Vernemmen I, Van Steenkiste G, Decloedt A, Meert H, Walser U, van Loon G. Detection of paroxysmal atrial fibrillation preceding persistent atrial fibrillation in a horse using an implantable loop recorder with remote monitoring. J Vet Cardiol 2024; 52:19-27. [PMID: 38402667 DOI: 10.1016/j.jvc.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/02/2024] [Accepted: 02/04/2024] [Indexed: 02/27/2024]
Abstract
Implantable loop recorders (ILRs) are increasingly used in equine cardiology to detect arrhythmias in the context of collapse, poor performance or monitoring for recurrence of atrial fibrillation (AF). However to date, the ILR has never been reported to be used with a remote monitoring functionality in horses, therefore the arrhythmia is only discovered when a clinician interrogates the ILR using dedicated equipment, which might delay diagnosis and intervention. This case report describes the use of an ILR with remote monitoring functionality in a horse with recurrent AF. The remote monitoring consisted of a transmission device located in the stable allowing daily transmission of arrhythmia recordings and functioning messages to an online server, available for the clinician to evaluate without specialised equipment. The ILR detected an episode of paroxysmal AF approximately 3 months after implantation. Seven months after implantation, initiation of persistent AF was seen on an episode misclassified by the ILR as bradycardia, and the horse was retired. This report shows the feasibility and benefits of remote monitoring for ILRs in horses, but also the shortcomings of current algorithms to interpret the equine electrocardiogram.
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Affiliation(s)
- I Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
| | - G Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - A Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - H Meert
- Biotronik Belgium, Medialaan 36, 1800 Vilvoorde, Belgium
| | - U Walser
- Biotronik Belgium, Medialaan 36, 1800 Vilvoorde, Belgium
| | - G van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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11
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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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Hsue W, Gagnon AL. Treating Stubborn Cardiac Arrhythmias-Looking Toward the Future. Vet Clin North Am Small Anim Pract 2023; 53:1415-1428. [PMID: 37541824 DOI: 10.1016/j.cvsm.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2023]
Abstract
As animals can develop significant side effects or remain refractory while on antiarrhythmic medical therapy for tachyarrhythmias, interventional therapies are progressively being explored. This review will highlight the principles and utilities of implantable cardioverter-defibrillators, electrophysiological mapping and catheter ablation, three-dimensional electroanatomical mapping, and stereotactic arrhythmia radiotherapy. In particular, three-dimensional electroanatomical mapping is emerging as an adjunct electrophysiology tool to facilitate activation, substrate, and pace mapping for intuitive analysis of complex tachyarrhythmias. Unlike antiarrhythmic medications, these modalities offer potential for decreasing risk of sudden death and even permanent termination of tachyarrhythmias.
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Affiliation(s)
- Weihow Hsue
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, 930 Campus Road, Ithaca, NY 14853, USA.
| | - Allison L Gagnon
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California - Davis, One Shields Avenue, Davis, CA 95616, USA.
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13
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Massie SL, Bezugley RJ, McDonald KJ, Léguillette R. Training vs. racing: A comparison of arrhythmias and the repeatability of findings in Thoroughbred Chuckwagon racehorses. Vet J 2023; 300-302:106040. [PMID: 37898456 DOI: 10.1016/j.tvjl.2023.106040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 10/30/2023]
Abstract
Arrhythmias are commonly reported in exercising horses, however due to regulatory constraints electrocardiograms (ECGs) are acquired during training but not competition, raising questions about the repeatability of findings. The aims were (1) compare training and competition arrhythmias and (2) describe the repeatability of arrhythmias during maximal-intensity exercise. A convenience sample of 52 healthy Thoroughbreds (aged 8.7 ± 2.5 years) competing in the World Professional Chuckwagon Association were obtained, totaling 152 training or competition ECGs (2-7 ECGs/horse). Speed, heart rate (HR) and arrhythmias (supraventricular premature complex, SVPC; ventricular premature complex, VPC) were examined. Pre- and post-recovery (approximately 6 min) blood samples measured lactate and high-sensitivity troponin-T. Training and competition arrythmias were compared (Friedman's test) and reliability of repeated ECGs assessed (intraclass correlation; P < 0.05). Training vs. competition: Forty horses had clean tracing from training and competition (n = 80 ECGs); the number and type of arrhythmias were not different. In training, VPCs were present in 7/40 horses (median [interquartile range, IQR]/ECG; range; 0 [0,0]; 0-4) and 9/40 horses (0 [0,0]; 0-5) in active-recovery. In competition, VPCs were present in 7/40 horses (0 [0,0]; 0-8) and 8/40 horses (0 [0,0]; 0-5) in active-recovery. Arrhythmias were primarily single premature complexes. Training and competition speed, HR, lactate and troponin-T did not differ however, sampling was too early for peak serum Troponin-T levels. Repeatability: total arrhythmias between serial ECGs did not differ. The reliability to detect SVPCs and VPCs was poor to moderate, and poor, respectively. Overall, the total number of arrhythmias was repeatable, but the reliability of arrhythmia type was poor to moderate.
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Affiliation(s)
- S L Massie
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - R J Bezugley
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - K J McDonald
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada
| | - R Léguillette
- Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4Z6, Canada.
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14
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Buschmann E, Van Steenkiste G, Boussy T, Vernemmen I, Schauvliege S, Decloedt A, van Loon G. Three-dimensional electro-anatomical mapping and radiofrequency ablation as a novel treatment for atrioventricular accessory pathway in a horse: A case report. J Vet Intern Med 2023; 37:728-734. [PMID: 36866668 PMCID: PMC10061177 DOI: 10.1111/jvim.16668] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 02/07/2023] [Indexed: 03/04/2023] Open
Abstract
We describe the diagnosis and treatment of an atrioventricular accessory pathway (AP) in a horse using 3-dimensional electro-anatomical mapping (3D EAM) and radiofrequency catheter ablation (RFCA). During routine evaluation of the horse, intermittent ventricular pre-excitation was identified on the ECG, characterized by a short PQ interval and abnormal QRS morphology. A right cranial location of the AP was suspected from the 12-lead ECG and vectorcardiography. After precise localization of the AP using 3D EAM, ablation was performed and AP conduction was eliminated. Immediately after recovery from anesthesia an occasional pre-excited complex still was observed, but a 24-hour ECG and an ECG during exercise 1 and 6 weeks after the procedure showed complete disappearance of pre-excitation. This case shows the feasibility of 3D EAM and RFCA to identify and treat an AP in horses.
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Affiliation(s)
- Eva Buschmann
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Glenn Van Steenkiste
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Tim Boussy
- Department of CardiologyAZ GroeningeKortrijkBelgium
| | - Ingrid Vernemmen
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Stijn Schauvliege
- Department of Large Animal Surgery, and Anaesthesia and Orthopaedics, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
| | - Gunther van Loon
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary MedicineGhent UniversityMerelbekeBelgium
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15
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Decloedt A. Implantable loop recorders for detecting arrhythmia in horses: Research tool or diagnostic technique? EQUINE VET EDUC 2023. [DOI: 10.1111/eve.13778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Annelies Decloedt
- Equine Cardioteam Ghent, Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine Ghent University Merelbeke Belgium
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