Speckle-Tracking Echocardiography in Dogs: Evaluating Imaging Parameters and Methodological Variability in Global Longitudinal Strain Assessment

Figures

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  Figure 1. Schematic illustration of three left apical views and probe placement used to measure automated function imaging and quantitative analysis for 2D strain. (A) Illustrates an apical four-chamber view (septal and lateral wall); (B) Illustrates an apical two-chamber view (anterior and inferior wall); (C) Illustrates an apical long-axis view (posterior and anterior septal wall); (D) Global longitudinal strain (GLS) by speckle-tracking echocardiography. A Bullseye from a healthy dog with a GLS of −17.7%. The Bullseye shows regional longitudinal strain for each segment of a 17-segment left ventricle model. Bright red shows the most negative normal values of GLS. The grey circle represents the indicator placement of the ultrasound probe (A–C).

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  Figure 2. Assessment of global longitudinal strain (GLS) in an optimized versus a foreshortened apical four-chamber (A4C) view in a healthy miniature Bull Terrier using 2D speckle-tracking echocardiography (2D STE). (A): 2D STE trace from an optimized A4C view with appropriate apical imaging. The segmental longitudinal strain curves (colored lines) correspond to the six myocardial segments of the left ventricle in this view, illustrating synchronized myocardial shortening with a calculated GLS of −16.7%. (B): The optimized A4C view in end-diastole demonstrates a long-axis measurement from the mitral annulus to the apex of 41.44 mm. (C): Optimized A4C view in systole. The green arrow indicates the true apex, which appears smooth, pointed, and normally contracting, confirming the absence of foreshortening. (D): Foreshortened A4C view with altered image geometry. The 2D STE-derived strain curves (colored lines) show increased segmental strain values and a falsely elevated GLS of −20.9%, despite identical patient and imaging conditions. (E): Foreshortened A4C view in end-diastole, showing a reduced LV long-axis length of 34.25 mm, consistent with incomplete apical visualization. (F):…

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  Figure 3. Bland–Altman plots comparing the 2D strain and AFI measurements. Solid line—mean difference between 2D strain and AFI, dashed lines—the limits of agreement, dotted lines—95% confidence intervals for the mean difference. The plots shown are GLS (top left), GLSAPLAX (top right), GLSA4C (bottom left), and GLSA2C (bottom right).