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Cardiovascular digital health journal2022; 3(2); 96-106; doi: 10.1016/j.cvdhj.2022.02.001

Detecting paroxysmal atrial fibrillation from normal sinus rhythm in equine athletes using Symmetric Projection Attractor Reconstruction and machine learning.

Abstract: Atrial fibrillation (AF) is a common cardiac arrhythmia in both human and equine populations. It is associated with adverse outcomes in humans and decreased athletic performance in both populations. Paroxysmal atrial fibrillation (PAF) presents with intermittent, self-terminating AF episodes, and is difficult to diagnose once sinus rhythm resumes. Unassigned: We aimed to detect PAF subjects from normal sinus rhythm equine electrocardiograms (ECGs) using the Symmetric Projection Attractor Reconstruction (SPAR) method to encapsulate the waveform morphology and variability as the basis of a machine learning classification. Unassigned: We obtained ECG signals from 139 active equine athletes (120 control, 19 with a PAF diagnosis). The SPAR method was applied to 9 short (20-second) ECG strips for each subject. An optimal SPAR feature set was determined by forward feature selection for input to a machine learning model ensemble of 3 different classifiers (k-nearest neighbors, linear support vector machine, and radial basis function kernel support vector machine). Imbalanced data were handled by upsampling the minority (PAF) class. A final subject classification was made by taking a majority vote over results from the 9 ECG strips. Unassigned: Our final cross-validated classification for a subject gave an accuracy of 89.0%, sensitivity of 94.8%, specificity of 87.1%, and receiver operating characteristic area under the curve of 0.98, taking PAF as the positive class. Unassigned: The SPAR method and machine learning generated a final model with high sensitivity, suggesting that PAF can be discriminated from short equine ECG strips. This preliminary study indicated that SPAR analysis of human ECG could support patient monitoring, risk stratification, and clinical decision-making.
Publication Date: 2022-02-14 PubMed ID: 35493267PubMed Central: PMC9043370DOI: 10.1016/j.cvdhj.2022.02.001Google Scholar: Lookup
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  • Journal Article

Summary

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The research article focused on the application of Symmetric Projection Attractor Reconstruction (SPAR) and machine learning to detect paroxysmal atrial fibrillation (an intermittent form of irregular heart rhythm) in horses. The study involved analyzing electrocardiograms of equine athletes and demonstrated high accuracy in differentiating horses with and without this heart condition.

Objective of the Study

  • The aim of the research was to differentiate horses with paroxysmal atrial fibrillation (PAF) from their healthy counterparts. The focus area was to develop a reliable machine learning model using the Symmetric Projection Attractor Reconstruction (SPAR) method, which maps waveform shapes and variations to identify PAF instances from short electrocardiogram (ECG) strips.

Methodology

  • The researchers sourced ECG recordings from 139 active equine athletes consisting of 120 control (healthy) and 19 diagnosed with PAF.
  • Each of the subjects had their heart’s electrical activity captured in nine short (20-second) ECG recordings, which were subsequently analyzed via the SPAR technique.
  • The team identified the most valuable SPAR features for the machine learning model through a forward feature selection process. The model created was an ensemble of three different classifiers, namely k-nearest neighbors, linear support vector machine, and radial basis function kernel support vector machine.
  • As the dataset was imbalanced (more healthy horses than those diagnosed with PAF), the researchers handled this by upsampling the minority (PAF) class to balance it with the majority class.
  • The final classification for each horse was achieved by taking the majority vote from the results of the nine ECG strips.

Results of the Study

  • The researchers were quite successful in their endeavor, with the final cross-validated model showing an accuracy rate of 89.0%. The machine learning model’s sensitivity and specificity were 94.8% and 87.1%, respectively, with a receiver operating characteristic area under the curve of 0.98, taking PAF as the positive class.
  • This suggests that the SPAR method combined with machine learning can accurately distinguish PAF from short equine ECG strips.

Potential Applications

  • The results of the study suggest that the SPAR technique has potential applications beyond veterinary science. It could be used to analyze human ECG readings to improve patient monitoring, risk stratification, and clinical decision-making processes.

Cite This Article

APA
Huang YH, Lyle JV, Ab Razak AS, Nandi M, Marr CM, Huang CL, Aston PJ, Jeevaratnam K. (2022). Detecting paroxysmal atrial fibrillation from normal sinus rhythm in equine athletes using Symmetric Projection Attractor Reconstruction and machine learning. Cardiovasc Digit Health J, 3(2), 96-106. https://doi.org/10.1016/j.cvdhj.2022.02.001

Publication

ISSN: 2666-6936
NlmUniqueID: 101771268
Country: United States
Language: English
Volume: 3
Issue: 2
Pages: 96-106

Researcher Affiliations

Huang, Ying H
  • Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.
  • Department of Mathematics, University of Surrey, Guildford, United Kingdom.
Lyle, Jane V
  • Department of Mathematics, University of Surrey, Guildford, United Kingdom.
Ab Razak, Anisa Shahira
  • Department of Veterinary Medicine, University of Cambridge, Madingley Rd, Cambridge, United Kingdom.
Nandi, Manasi
  • School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom.
Marr, Celia M
  • Rossdales Equine Hospital and Diagnostic Centre, Newmarket, United Kingdom.
Huang, Christopher L-H
  • Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.
  • Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom.
Aston, Philip J
  • Department of Mathematics, University of Surrey, Guildford, United Kingdom.
Jeevaratnam, Kamalan
  • Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.

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Citations

This article has been cited 3 times.
  1. Kapusniak A, Lara NM, Hitchens PL, Bailey S, Nath L, Franklin S. Use of Artificial Intelligence to Detect Cardiac Rhythm Disturbances in Athletes: A Scoping Review. J Vet Intern Med 2025 Nov-Dec;39(6):e70257.
    doi: 10.1111/jvim.70257pubmed: 41017277google scholar: lookup
  2. Akbarein H, Taaghi MH, Mohebbi M, Soufizadeh P. Applications and Considerations of Artificial Intelligence in Veterinary Sciences: A Narrative Review. Vet Med Sci 2025 May;11(3):e70315.
    doi: 10.1002/vms3.70315pubmed: 40173266google scholar: lookup
  3. Zhang Z, Hirose K, Yamada K, Sato D, Uchida K, Umezu S. A periodic split attractor reconstruction method facilitates cardiovascular signal diagnoses and obstructive sleep apnea syndrome monitoring. Heliyon 2024 Aug 15;10(15):e35623.
    doi: 10.1016/j.heliyon.2024.e35623pubmed: 39170365google scholar: lookup