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BMC cardiovascular disorders2019; 19(1); 228; doi: 10.1186/s12872-019-1210-4

Longitudinal study of electrical, functional and structural remodelling in an equine model of atrial fibrillation.

Abstract: Large animal models are important in atrial fibrillation (AF) research, as they can be used to study the pathophysiology of AF and new therapeutic approaches. Unlike other animal models, horses spontaneously develop AF and could therefore serve as a bona fide model in AF research. We therefore aimed to study the electrical, functional and structural remodelling caused by chronic AF in a horse model. Nine female horses were included in the study, with six horses tachypaced into self-sustained AF and three that served as a time-matched sham-operated control group. Acceleration in atrial fibrillatory rate (AFR), changes in electrocardiographic and echocardiographic variables and response to medical treatment (flecainide 2 mg/kg) were recorded over a period of 2 months. At the end of the study, changes in ion channel expression and fibrosis were measured and compared between the two groups. AFR increased from 299 ± 33 fibrillations per minute (fpm) to 376 ± 12 fpm (p < 0.05) and atrial function (active left atrial fractional area change) decreased significantly during the study (p < 0.05). No changes were observed in heart rate or ventricular function. The AF group had more atrial fibrosis compared to the control group (p < 0.05). No differences in ion channel expression were observed. Horses with induced AF show signs of atrial remodelling that are similar to humans and other animal models.
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Publication Date: 2019-10-21 PubMed ID: 31638896PubMed Central: PMC6805623DOI: 10.1186/s12872-019-1210-4Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research paper investigates the changes in heart structure, function, and electrical activities in horses that suffer from chronic atrial fibrillation (AF). The study’s findings suggest that horses with artificially induced AF show signs of atrial remodeling similar to humans and other animal models.

Understanding the Study

  • The main objective of this research was to explore the structural, functional, and electrical changes caused by chronic AF in horses. The reason for using horses as a subject for this study is that they often develop AF naturally, making them a potentially valid model for studying this heart condition.
  • The scientists involved in this research used a total of nine female horses. Six of these horses were put into a state of self-supported AF through tachypacing – a technique whereby the heart rate is artificially increased. The remaining three horses comprise the control group, subjected to sham operations that mimic the actual procedure but without its true effect, ensuring comparison between normal and affected conditions.
  • The researchers used various methods to track the progression of this heart condition in the horses. They monitored changes in the heart rate of fibrillations, observed shifts in electrocardiographic and echocardiographic variables, and studied the responses to a specific medical treatment (flecainide). All these records were noted over a timeframe of two months.

Key Findings

  • The measure of the atrial fibrillatory rate (AFR) rose significantly during the study period – from 299±33 fibrillations per minute (fpm) to 376±12 fpm. The study confirmed that the rate of fibrillations increases with time in the case of chronic AF.
  • There was a significant decrease in active left atrial fractional area change, suggesting a reduction in atrial function during the experiment.
  • No changes were observed in either heart rate or the performance of the ventricles, implying that effects of AF are primarily confined to atria.
  • The AF group had more cases of atrial fibrosis (tissue thickening and scarring in the atrium) compared to the control group, pointing to structural changes being part of AF’s influence.
  • The scientists observed no changes in ion channel expression between the two groups of horses, indicating that this aspect may be less influenced by chronic AF.
  • Importantly, the study found that induced AF in horses shows remodeling patterns in the heart that are similar to humans and other animal models, endorsing the validity of horses as a reliable model for studying AF.

Implications of the Research

  • This study validates the role of horses in AF research, as the impact of AF on their hearts reflects the progression of this condition in humans. The findings, therefore, could be applied to improve our understanding of AF and its management in humans.
  • The study highlights the importance of large animal models in AF research, providing a more realistic basis for studying the pathophysiology of this cardiac condition and evaluating the effectiveness of therapeutic interventions.
  • The findings also point towards the potential structural and functional changes that AF may induce in the afflicted heart, furthering our understanding of AF’s impact on cardiac health.

Cite This Article

APA
Hesselkilde EZ, Carstensen H, Flethøj M, Fenner M, Kruse DD, Sattler SM, Tfelt-Hansen J, Pehrson S, Braunstein TH, Carlson J, Platonov PG, Jespersen T, Buhl R. (2019). Longitudinal study of electrical, functional and structural remodelling in an equine model of atrial fibrillation. BMC Cardiovasc Disord, 19(1), 228. https://doi.org/10.1186/s12872-019-1210-4

Publication

BMC cardiovascular disorders
ISSN: 1471-2261
NlmUniqueID: 100968539
Country: England
Language: English
Volume: 19
Issue: 1
Pages: 228

Researcher Affiliations

Hesselkilde, Eva Zander
  • Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark.
Carstensen, Helena
  • Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark.
Flethøj, Mette
  • Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark.
Fenner, Merle
  • Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark.
Kruse, Ditte Dybvald
  • Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
Sattler, Stefan M
  • Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark.
  • Department of Medicine I, University Hospital Munich, Campus Grosshadern, Ludwig-Maximilians University Munich (LMU), Munich, Germany.
Tfelt-Hansen, Jacob
  • Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark.
  • Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederik V's vej 11, 2100, Copenhagen, Denmark.
Pehrson, Steen
  • Department of Cardiology, The Heart Centre, Copenhagen University Hospital, Blegdamsvej 9, 2100, Copenhagen, Denmark.
Braunstein, Thomas Hartig
  • Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
Carlson, Jonas
  • Department of Cardiology, Clinical Sciences, Arrhythmia Clinic, Skåne University Hospital, Lund University, 21185, Lund, Sweden.
Platonov, Pyotr G
  • Department of Cardiology, Clinical Sciences, Arrhythmia Clinic, Skåne University Hospital, Lund University, 21185, Lund, Sweden.
Jespersen, Thomas
  • Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
Buhl, Rikke
  • Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Højbakkegaard Allé 5, 2630, Taastrup, Denmark. rib@sund.ku.dk.

MeSH Terms

  • Action Potentials / drug effects
  • Animals
  • Anti-Arrhythmia Agents / pharmacology
  • Atrial Fibrillation / drug therapy
  • Atrial Fibrillation / etiology
  • Atrial Fibrillation / metabolism
  • Atrial Fibrillation / physiopathology
  • Atrial Function, Left / drug effects
  • Atrial Remodeling / drug effects
  • Cardiac Pacing, Artificial
  • Disease Models, Animal
  • Female
  • Fibrosis
  • Flecainide / pharmacology
  • Heart Atria / drug effects
  • Heart Atria / metabolism
  • Heart Atria / physiopathology
  • Heart Rate / drug effects
  • Horses
  • Ion Channels / metabolism
  • Time Factors

Conflict of Interest Statement

The authors declare that they have no competing interests.

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