MITRAL ANNULUS MOTION AS DETERMINED BY M-MODE ECHOCARDIOGRAPHY IN NORMAL DOGS AND DOGS WITH CARDIAC DISEASE

Authors

  • Karsten E. Schober Dr MedVet,

    Corresponding author
    1. Department of Small Animals, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 57, 04103 Leipzig, Germany
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  • Virginia Luis Fuentes PhD, MRCVS

    1. Department of Veterinary Clinical Studies, Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh, Scotland (UK).
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  • Dr. Schober was supported in parts by grants from the German Academic Exchange Service (DAAD), Bonn, Germany, and the Max Kade Foundation Inc., New York City, N.Y., USA.

  • Presented in parts at the 18th Annual Veterinary Medical Forum, Seattle, 24–28 May 2000.

Address correspondence and reprint requests to: Dr. K.E. Schober, Department of Small Animals, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 57, 04103 Leipzig, Germany.

Abstract

M-mode echocardiography was used to assess apical mitral annulus motion (MAM) in 103 normal dogs and 101 dogs with cardiac disease, to obtain information on systolic left ventricular long axis function. In normal dogs, a close relationship was found between MAM and body weight (r = 0.80, P < 0.001). There was a weak correlation between MAM and heart rate (r =−0.25, P < 0.05), but no correlation between MAM and age or left ventricular shortening fraction (P > 0.05). Mean MAM (95% confidence intervals) were established for normal dogs of differing body weight, and were 0.70 cm (0.65 to 0.75) in dogs < 15 kg, 1.08 cm (1.03 to 1.13) in dogs weighing 15 to 40 kg, and 1.51 cm (1.21 to 1.81) in dogs > 40 kg. “Cut-off” values to define decreased MAM for normal dogs of differing body weight were 0.45 cm (dogs < 15 kg), 0.80 cm (dogs 15–40 kg), and 1.20 cm (dogs > 40 kg). In dogs with cardiac disease, median MAM was normal in mitral valve endocardiosis or aortic stenosis, but significantly decreased (P < 0.05) in dilated cardiomyopathy. All dogs with mitral valve endocardiosis (n = 54) or aortic stenosis (n = 26) had MAM above the above-mentioned “cut-off” values, suggesting normal or increased left ventricular longitudinal systolic shortening, whereas 81 % (17/21) of dogs with dilated cardiomyopathy had MAM below the “cut-off value”, indicating decreased long axis systolic function. It is concluded that MAM may be used to evaluate systolic left ventricular long axis performance in dogs and may add useful information on global left ventricular contraction dynamics.

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