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. 2020 Sep;34(5):1779-1786.
doi: 10.1111/jvim.15850. Epub 2020 Jul 9.

Reproducibility of echocardiographic indices of left atrial size in dogs with subclinical myxomatous mitral valve disease

Weihow Hsue  1 , Lance C Visser  1
Affiliations

Reproducibility of echocardiographic indices of left atrial size in dogs with subclinical myxomatous mitral valve disease

Weihow Hsue et al. J Vet Intern Med. 2020 Sep.

Abstract

Background: Reliability of echocardiographic measurements of left atrial (LA) size, an important marker of disease severity, has not been reported in dogs with myxomatous mitral valve disease (MMVD).

Objectives: To define and compare reliability of left atrial dimension/diameter (LAD), LAD indexed to aortic valve diameter (LAD/AoD), left atrium-to-aortic root ratio (LA/Ao), left atrial volume acquired from a right parasternal long-axis (LAVRPLx ), and left apical view (LAVLAP ) in dogs with subclinical MMVD.

Animals: Nine dogs with subclinical MMVD.

Methods: Prospective reproducibility study. Dogs underwent 12 echocardiographic examinations by 2 operators on the mornings and afternoons of 3 nonconsecutive days within 1 week. Reliability (measurement variability) was quantified using coefficients of variation (CV) and 95% repeatability/reproducibility coefficients (95% RC). A mixed-model analysis of variance (ANOVA) was used to determine if time of day, day, and operator were significant sources of variability for each index.

Results: Linear measurements (LAD, LAD/AoD, and LA/Ao) exhibited less within-day, between-day, and interoperator variability (CVs, 3.9%-12.5%) than did volume estimate measurements (LAVRPLx and LAVLAP ; CVs, 11.8%-17.9%). Of the linear measurements, LA/Ao exhibited greater variability (CVs, 9.9%-12.5%) compared to LAD and LAD/AoD (CVs, 3.9%-4.9%). Operator was a significant (P = .005) source of variability for LA/Ao.

Conclusions and clinical importance: Compared to other linear measurements, LA/Ao was the least reproducible and most dependent on operator. The 95% RC for each LA size index are provided to help identify clinically relevant changes (beyond intraoperator or interoperator variability) during serial echocardiographic examinations of dogs with subclinical MMVD.

Keywords: canine; echocardiography; endocardiosis; left atrium; preclinical; reliability; repeatability.

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Conflict of interest statement

Authors declare no conflict of interest.

Figures

FIGURE 1
FIGURE 1
Scatter plots showing the reproducibility assessments between two operators for A, left atrial dimension (LAD); B, LAD indexed to aortic valve diameter (LAD/AoD); C, left atrium to aortic root ratio (LA/Ao); D, left atrial volume acquired from the right parasternal long‐axis view (LAVRPLx); and E, left atrial volume acquired from the left apical 4‐chamber view (LAVLAP). Nine dogs with subclinical myxomatous mitral valve disease had 12 echocardiographic examinations (6 per operator) performed over 1 week. The dashed line represents the line of equality (perfect agreement) and the solid (black) line represents the line of best fit. Spearman correlation coefficients (r s) are also presented
See this image and copyright information in PMC

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