• Open Access

Longitudinal Electrocardiographic Evaluation of Dogs with Degenerative Mitral Valve Disease

Authors

  • J. López-Alvarez,

    Corresponding author
    1. Department of Clinical Science and Services, Royal Veterinary College, London, UK
    • Corresponding author: J. López-Alvarez, Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK; e-mail: jlopezalvarez@rvc.ac.uk.

    Search for more papers by this author
  • A. Boswood,

    1. Department of Clinical Science and Services, Royal Veterinary College, London, UK
    Search for more papers by this author
  • W. Moonarmart,

    1. Department of Clinical Science and Services, Royal Veterinary College, London, UK
    Current affiliation:
    1. Faculty of Veterinary Science, Department of Clinical Sciences and Public Health, Mahidol University, Nakhon Pathom, Thailand
    Search for more papers by this author
  • M.J. Hezzell,

    1. Department of Clinical Science and Services, Royal Veterinary College, London, UK
    Current affiliation:
    1. Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
    Search for more papers by this author
  • N. Lotter,

    1. Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
    Search for more papers by this author
  • J. Elliott

    1. Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
    Search for more papers by this author

Abstract

Background

Increased heart rate (HR) and decreased heart rate variability (HRV) are evident in some dogs with degenerative mitral valve disease (DMVD).

Objectives

Evaluation of the factors influencing HR and HRV (assessed by the vasovagal tonus index; VVTI) and their change over time in dogs with DMVD.

Animals

Client-owned dogs (n = 257) with DMVD recruited from first opinion practice.

Methods

Prospective longitudinal follow-up at six-monthly intervals of dogs with DMVD. Dogs followed up for at least 18 months (n = 102) were grouped according to their outcome as dogs dying/euthanized because of cardiac disease (n = 28; Group 1), noncardiac disease (n = 40; Group 2) and dogs alive (n = 34; Group 3). HR and VVTI were measured on 1-minute ECG recordings. Repeated measures linear models were constructed to investigate the factors that influence HR and VVTI and their changes over time.

Results

Heart rate and VVTI were affected by disease severity and were different in Cavaliers compared to other breeds. Group 1 and Group 2 dogs underwent an increase in HR and decrease in VVTI, evident at least 18 months before death. Group 1 had a further decrease in VVTI followed by an increase in HR approximately 1 year and 6 months before death, respectively.

Conclusions and Clinical Importance

Dogs with DMVD have an increase in HR and decrease in HRV over a year before death, with greater changes in those dogs dying/euthanized because of cardiac disease. Both HR and VVTI can potentially be regarded as biomarkers for all-cause mortality.

Ancillary