Spatio-temporal Organization During Ventricular Fibrillation in the Human Heart

Figures

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  Figure 1. Representation of epicardial sock with the spatial coordinates of the epicardial electrodes (black circles) with respect to left and right ventricles (LV and RV). (a) Three-dimensional view of electrodes; (b) projection of electrodes onto flat two-dimensional surface.

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  Figure 2. Results from complex network analysis for Patient H055. Each row shows a VF epoch of 30 s duration. (A) controlled VF (Control), (B)–(F) global myocardial ischaemia (Isch1–5), (G) reflow. (a) Correlation matrices; (b) network structure representation with network connections thresholded at value of 0.7; (c) highly correlated nodes from node centrality measure (red circles); (d) clusters from hierarchical clustering; electrodes in same clusters are shown with same colour. Electrodes which do not form a cluster are shown by white circles.

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  Figure 3. Temporal changes in the quantitative measure of overall organization in correlation matrices during controlled ventricular fibrillation (Control), global myocardial ischaemia (Isch1–5) and reflow across recordings. (a) Normalized Frobenius norm measure; (b) Piece-wise linear fit for the normalized Frobenius norm during VF episodes.

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  Figure 4. Temporal changes in the quantitative measures from network analysis during controlled ventricular fibrillation (Control), global myocardial ischaemia (Isch1–5) and reflow across recordings. (a) AUC measure of connection density; (b) AUC measure of average clustering co-efficient. Error bar shows the averaged trend from piece-wise linear fit across patients.

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  Figure 5. Temporal changes in the AUC of normalized number of clusters during controlled ventricular fibrillation (Control), global myocardial ischaemia (Isch1–5) and reflow across recordings. Error bar shows the averaged trend from piece-wise linear fit across patients.

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  Figure 6. Temporal changes in the average number of phase singularities during controlled ventricular fibrillation (Control), global myocardial ischaemia (Isch1–5) and reflow across recordings.Error bar shows the averaged trend from piece-wise linear fit across patients.

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  Figure 7. Principal component feature space of complexity measures during controlled VF (control), global myocardial ischaemia (Isch1–5) and reflow. Number of phase singularities (*), number of clusters (•) and difference between the principal components of two quantities are shown in dashed lines.