Speckle tracking stress echocardiography in children: interobserver and intraobserver reproducibility and the impact of echocardiographic image quality

Figures

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  Figure 1. Schematic diagram outlining the experimental setup of speckle tracking echocardiography at baseline and during bicycle ergometer stress testing.

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  Figure 2. Bland-Altman graphic demonstrating the reproducibility of circumferential strain. (A) Interobserver variability of circumferential strain at baseline. (B) Interobserver variability of circumferential strain during exercise testing. (C) Intraobserver variability of circumferential strain at baseline. (D) Intraobserver variability of circumferential strain during exercise testing. The blue dashed line indicates the mean bias (mean difference) and the red dashed lines represent the limits of agreement.

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  Figure 3. Bland-Altman graphic: reproducibility of circumferential strain rate. (A) Interobserver variability of circumferential strain rate at baseline. (B) Interobserver variability of circumferential strain rate during exercise testing. (C) Intraobserver variability of circumferential strain rate at baseline. (D) Intraobserver variability of circumferential strain rate during exercise testing. The blue dashed line indicates the mean bias (mean difference) and the red dashed lines represent the limits of agreement.

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  Figure 4. Bland-Altman graphic: reproducibility of longitudinal strain. (A) Interobserver variability of longitudinal strain at baseline. (B) Interobserver variability of longitudinal strain during exercise testing. (C) Intraobserver variability of longitudinal strain at baseline. (D) Intraobserver variability of longitudinal strain during exercise testing. The blue dashed line indicates the mean bias (mean difference) and the red dashed lines represent the limits of agreement.

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  Figure 5. Bland-Altman graphic: reproducibility of longitudinal strain rate. (A) Interobserver variability of longitudinal strain rate at baseline. (B) Interobserver variability of longitudinal strain rate during exercise testing. (C) Intraobserver variability of longitudinal strain rate at baseline. (D) Intraobserver variability of longitudinal strain rate during exercise testing. The blue dashed line indicates the mean bias (mean difference) and the red dashed lines represent the limits of agreement.

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  Figure 6. Scatterplots of strain and strain rate measurement inter-rater variability subject to echocardiographic image quality. (A) Circumferential strain. (B) Circumferential strain rate. (C) Longitudinal strain. (D) Longitudinal strain rate.

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  Figure 7. Scatterplots of strain and strain rate measurement intra-rater day-to-day variability subject to echocardiographic image quality. (A) Circumferential strain. (B) Circumferential strain rate. (C) Longitudinal strain. (D) Longitudinal strain rate.