Accurate QT correction method from transfer entropy

Figures

• 

  Figure 1. A: Illustration of information transfer from previous R-R intervals to the present QT interval. B: Examples of transition probabilities. The intersection of the distributions as a function of QTi yields zero transfer entropy and thus candidates for the selection of the corrected QT interval (QTc).

• 

  Figure 2. A-D: QT(c) values as a function of the corresponding R-R intervals (RRIs) for the complete PhysioNet dataset (>120,000 interval pairs), presented as point clouds (left) and box plots (right). The horizontal dashed lines denote the normal 350–450 ms range. The percentages on the right denote the proportion of points located in the normal range. See text for details.

• 

  Figure 3. R-R interval (RRI)-QT(c) point clouds for the 6 longest recordings of the PhysioNet dataset. In the Bazett and AccuQT clouds the colors indicate the shift from the raw QT values (QTc-QT).

• 

  Figure 4. A-F: QT(c) values as a function of the corresponding R-R intervals (RRIs) for the THEW dataset (>18 million interval pairs) presented as point clouds. The density is normalized to the range 0–1. The horizontal dashed lines denote the normal 350–450 ms range. The percentages denote the proportion of points located in the normal range. See text for details.

• 

  Figure 5. A: QT(c) values as a function of time for a 52-year-old healthy male subject from the THEW dataset. B: Corresponding R-R intervals. C: Corresponding RR-QT(c) clouds and the slopes obtained for all clouds with linear fitting. In (C) small noise (± 2.5 ms) has been added to the R-R intervals (quantized within 5 ms) for better visualization.