• Open Access

Advanced Electrocardiographic Parameters Change with Severity of Mitral Regurgitation in Cavalier King Charles Spaniels in Sinus Rhythm


  • The study was performed at the Institute of Physiology, Medical Faculty, University of Ljubljana, Slovenia; at the Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, University of Copenhagen, Denmark; at the Clinic for Surgery and Small Animal Medicine, Veterinary Faculty, University of Ljubljana, Slovenia; and at the small animal hospital Din Veterinar, Helsingborg, Sweden.
  • Preliminary data from this study were presented as a poster at the 2011 ACVIM Forum in Denver, Colorado.

Corresponding author: Vito Starc, MD, PhD, Faculty of Medicine, Institute of Physiology, University of Ljubljana, Zaloška 4, SI-1000 Ljubljana, Slovenia; E-mail: vito.starc@mf.uni-lj.si.



Multiple advanced resting ECG (A-ECG) techniques have improved the diagnostic or prognostic value of ECG in detecting human cardiac diseases even before onset of clinical signs or changes in conventional ECG.


To determine which A-ECG parameters, derived from 12-lead A-ECG recordings, change with severity of mitral regurgitation (MR) caused by myxomatous mitral valve disease (MMVD) in Cavalier King Charles Spaniels (CKCSs) in sinus rhythm.


Seventy-six privately owned CKCSs.


Dogs were prospectively divided into 5 groups according to the degree of MR (estimated by color Doppler mapping as the percentage of the left atrial area affected by the MR jet) and presence of clinical signs. High fidelity approximately 5-minute 12-lead ECG recordings were evaluated using custom software to calculate multiple conventional and A-ECG parameters.


Nineteen of 76 ECG parameters were significantly different (< .05) across the 5 dog groups. A 4-parameter model that incorporated results from 1 parameter of heart rate variability, 2 parameters of QT variability, and 1 parameter of QRS amplitude was identified that explained 82.4% of the variance with a correlation coefficient (R) of 0.60 (< .01). When age or murmur grade was included in the statistical model the prediction value further increased the R to 0.74 and 0.85 (< .01), respectively.


In CKCSs with sinus rhythm, 4 selected A-ECG parameters further improve prediction of MR jet severity beyond age and murmur grade, although the predictive increment in this study probably is not sufficient to warrant utilization in clinical veterinary practice.