Ischemic Stroke Risk Assessment by Multiscale Entropy Analysis of Heart Rate Variability in Patients with Persistent Atrial Fibrillation

Figures

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  Figure 1. Patient selection flowchart.

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  Figure 2. Fluctuation functions F(s) estimated by the detrended fluctuation analysis (DFA) of the morning recording. Comparison between stroke-naïve AFib patients who developed (blue triangle) and did not develop (red circle) an ischemic stroke during the observation period. The unit of s is seconds. Error bars represent the standard deviation, while dashed lines indicate the slopes with α1 = 0.64 and α2 = 0.89. No significant difference was found in the scaling exponents of DFA between the two groups.

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  Figure 3. Kaplan–Meier survival curves for ischemic stroke occurrence. The patients were stratified by (a) SE(s) ≥ 0.68 (blue line) and SE(s) < 0.68 (red line) at a time scale of 210 s of the morning recording and (b) SE(s) ≥ 0.78 (blue line) and SE(s) < 0.78 (red line) at a time scale of 270 s of the afternoon recording.

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  Figure 4. Cumulative incidence function for ischemic stroke occurrence and mortality. The patients were stratified by (a) SE(s) ≥ 0.68 (blue and green line) and SE(s) < 0.68 (red and black line) at a time scale of 210 s of the morning recording and (b) SE(s) ≥ 0.78 (blue and green line) and SE(s) < 0.78 (red and black line) at a time scale of 270 s of the afternoon recording. An asterisk (*) indicates p-value < 0.05, while double asterisks (**) indicates p-value < 0.01.

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  Figure 5. Cumulative incidence function for ischemic stroke occurrence and mortality. The patients were stratified by (a) autocorrelation coefficient at lag τ = 1 (R(s)(1)) ≥ 0.88 (blue and green line) and R(s)(1) < 0.88 (red and black line) at a time scale of 210 s of the morning recording and (b) R(s)(1) ≥ 0.81 (blue and green line) and R(s)(1) < 0.81 (red and black line) at a time scale of 270 s of the afternoon recording. An asterisk (*) indicates p-value < 0.05, while double asterisks (**) indicates p-value < 0.01.

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  Figure 6. Cumulative incidence function for ischemic stroke occurrence and mortality. The patients were stratified by (a) information entropy (HD(s)) ≥ 2.18 (blue and green line) and HD(s) < 2.18 (red and black line) at a time scale of 210 s of the morning recording and (b) HD(s) ≥ 2.15 (blue and green line) and HD(s) < 2.15 (red and black line) at a time scale of 270 s of the afternoon recording. An asterisk (*) indicates p-value < 0.05.