The electrocardiographic inverse problem

Using the boundary element method in conjunction with Tikhonov zero-order regularization, we have computed epicardial potentials from body surface potential data in a realistic geometry heart-torso system. The inverse-reconstructed epicardial potentials were compared to the actual measured potentials throughout a normal cardiac cycle. Potential features (maxima, minima) were recovered with an accuracy better than 1 cm in their location. In this chapter, we use these data to illustrate and discuss computational issues related to the inverse-reconstruction procedure. These include the boundary element method, the choice of a regularization scheme to stabilize the inversion, and the effects of incorporating a priori information on the accuracy of the solution. In particular, emphasis is on the use of temporal information in the regularization procedure. The sensitivity of the solution to geometrical errors and to the spatial and temporal resolution of the data is discussed.