We present a cardiac model of post-mortem heart that can be applied to quantitative analysis of electrocardiologic problems. Two adult postmortem hearts in the systolic state were photographed and then were subjected to MRI scanning. Hence, anatomical slicing was performed using an automatic cutter that created 3mm thick sections. The first one dissected vertical to its longitudinal axis, and the second one at the sagittal plane. Each section was further diced into smaller specimens for further histological process. All the microscopic slides were digitized in order to be used for histological sections reconstructing. The need to define the fiber orientation led us to create a specific drawing package in MATLAB® called FiberCad. For each point of the extracted model, information of the electrical characteristics and the prevalent fibers' orientation can be accurately modeled.

No abstract

Both the forward and inverse problems of electrocardiography rely on the precise modelling of the anatomic and electrical properties of the thoracic tissues. This, in turn, requires good knowledge of the electrical anisotropy as well as conductivity inhomogeneity of the heart, lungs and the rest of the thorax. Cardiac electrical anisotropy is related to its microstructure (fibre length, density and orientation). We hereby present detailed three-dimensional (3D) meshes of the thorax and heart, using image data from contiguous 2D magnetic resonance (MR) imaging slices as well as a realistic 3D cardiac fibre orientation model that derives its data from high-resolution ex vivo human heart MR images and from histology specimens of heart tissue. Using specific software, we integrated the 3D thorax and heart meshes in one that addresses the related modelling requirements for the solution of the forward and inverse problems of electrocardiography.