Multi-scale Entropy Evaluates the Proarrhythmic Condition of Persistent Atrial Fibrillation Patients Predicting Early Failure of Electrical Cardioversion

Figures

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  Figure 1. Example of a common electrocardiogram (ECG) segment (a), along with the extracted f-waves (b) by average QRST complex subtraction.

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  Figure 2. Boxplot distributions of the parameters previously proposed in the literature to predict ECV outcome, i.e., (a) f-waves amplitude (FWA), (b) normalized f-waves amplitude (nFWA) (c) dominant frequency (DF), and (d) Sample Entropy (SE). The central mark indicates the median, the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively, and the whiskers extend to the most extreme data points not considered outliers. The outliers are plotted using the symbol +.

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  Figure 3. Median values (symbol ◼) and interquartile ranges (whiskers) of (a) multi-scale entropy (MSE), (b) composite MSE (CMSE) and (c) refined MSE (RMSE) as a function of the time scale (τ) for patients maintaining SR and relapsing to AF at the end of the follow-up.

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  Figure 4. Boxplot distributions of AHS and SHS for (a) MSE, (b) CMSE, and (c) RMSE. The central mark indicates the median, the bottom and top edges of the box indicate the 25th and 75th percentiles, respectively, and the whiskers extend to the most extreme data points not considered outliers.

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  Figure 5. ROC curves for SE obtained from the best time scale, AHS and SHS derived from (a) MSE, (b) CMSE, (c) RMSE. The point marks optimal threshold according to the Youden’s criterion.