Table 1.
Patients cohort demographics.
Fig 1.
CT images were acquired in 10 or 20 frames over a whole cardiac cycle. The end-diastolic (ED) geometry was then selected and automatically segmented [31]. The resulting segmentation was post-processed to generate labels representing the RV, LA and RA myocardium, the wall thickness for the aorta and the pulmonary artery, valve planes and rings at the cropped veins. The surface of the segmentation was then smoothed [37] and all the labels but the blood pools and the LV papillary muscles were extracted to generate a tetrahedral mesh. We extracted the endocardial and epicardial surfaces of the atria and ventricles and we assigned fibre orientation to the ventricles with a rule-based method [38]. Finally, we simulated electrical activation and mechanical contraction of the ventricles to test the usability of the meshes.
Fig 2.
Twenty-four four-chamber heart meshes.
The images show an anterior view of the twenty-four meshes generated with the pipeline described in the text.
Fig 3.
The images on the left and in the center show an anterior and a posterior view of one of the four-chamber meshes. The image on the right shows an anterior view of a clip of the geometry. On the right, the twenty-four labels of the mesh are listed. The first row shows the myocardium of the LV, RV, LA, RA and the wall of the cropped aorta and pulmonary artery (PA). The second row shows the rings at the cropped veins and at the LAA. The third row shows the valve planes added at all inlets and outlets of the LV, RV, LA and RA.
Fig 4.
Universal ventricular coordinates.
From left to right: apico-basal coordinate, ranging between 0 at the apex and 1 at the base (anterior view); transmural coordinate, varying from 0 at the endocardium of the LV and of the RV free wall to 1 at the epicardium (top view); rotational coordinate, ranging between −π at the LV free wall, to 0 at the septum and π back to the LV free wall; intra-ventricular coordinate, defined at -1 at the LV and +1 at the RV.
Fig 5.
A The activation times computed by the eikonal model (shown on mesh 01 in the green box) trigger an upstroke in transmembrane potential Vm at each node of the mesh (orange curve in the orange box). When the transmembrane potential overcomes -60mV (black dashed line), the rise in active tension is triggered (blue curve in the blue box). B We show the changes in transmembrane potential (top row) and the active tension (bottom row) over time on mesh 01.
Table 2.
Passive and active mechanics material parameters.
Table 3.
The table shows the number of nodes, number of elements, average element quality (measured as the scaled Jacobian) and edge length for the twenty-four meshes. For the element quality and the edge length, we also reported the standard deviation within each mesh in brackets.
Fig 6.
A LV, RV, LA and RA volumes. B Area of the mitral, tricuspid, aortic and pulmonary valve planes. C LV and RV long-axis lengths. D LV diameter. All quantities are shown for the twenty-four meshes.
Fig 7.
The images show an anterior view of all meshes with the ventricles coloured according to the local activation time computed by the eikonal model. The grey regions were excluded by the eikonal solve and were therefore passive. The black structures represent the CRT leads segmented from the CT images. The RV lead was used as the initial activation point.
Table 4.
Electro-mechanics test simulations.
The table summarises results for the electro-mechanics simulation tests. For each mesh, we report the LV and RV latest activation times (LAT), the ejection fraction (EF) and the stroke volume (SV). The last row reports the mean ± the standard deviation of these values.
Fig 8.
Simulated free active contraction.
The images show the results for the free contraction simulations run on all meshes. For each mesh, we show the configuration at the end of LV systole (coloured according to the magnitude of the displacement vector ||u|| in mm) and the initial configuration (grey geometry).