Advanced electrocardiographic parameters change with severity of mitral regurgitation in Cavalier King Charles Spaniels in sinus rhythm.

Background: 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.

Objective: 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.

Animals: Seventy-six privately owned CKCSs.