A Review of the Forward Problem in Electrocardiographic Imaging

Figures

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  Figure 1. ECGI problem. ECGI reconstructs the electrical properties of the heart by recording the body-surface potential and the torso–heart geometry obtained from computer tomography (CT) or magnetic resonance (MR) imaging. The electrical properties of the reconstructed heart depend on the source model of the heart, which can be cardiac surface potential, activation/recovery time, or transmembrane voltage [26,29,30].

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  Figure 5. Some examples of applying TMV model. (a) Transmembrane action potentials (the source of cardiac electrical activity): (i) transmural (TM) heterogeneity in cells from the endocardium (ENDO), mid-myocardium (MCELL), and epicardium (EPI), (ii) apico-basal (AB) heterogeneity, and (iii) short single-cell action potentials. (b)The inputs and output of TMV model: (i) fiber orientation; (ii) heart–torso model; (iii) BSP, the output of the TMV model [153]. (c) Reconstruction of ventricular transmural action potentials [151].

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  Figure 2. Modeling methods of the ECGI forward problem.

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  Figure 3. Applications of CSP model: (a) Schematic diagram of a surface potential model. (b) The ventricular surface potential and corresponding EGM reconstructed by Cardio Insight [105]. (c) The comparison of recorded epicardial potentials and reconstructed epicardial potentials from the CSP model [26]. (d) The input (epicardial potentials) and output (BSPs) of the CSP model [29].

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  Figure 4. Some examples of applying EDL model. (a) Reconstruction of the ventricular endocardium and epicardium polarization times [5]. (b) The input of EDL model: anterior and superior views of the heart (with spheres indicating electrode and color for RT). (c) Superimposed measured (blue) and reconstructed (red) body-surface ECGs [4].