Implicit and explicit constraints in inverse electrocardiography.

This paper reviews the major distributed source models that have been postulated over the years to support the interpretation of observed body surface potentials: double-layer models, the source description in terms of epicardial (ie, pericardial) potentials, and its equivalent: the distributed monolayer. This includes a presentation and discussion of a source model that has been developed over the past decade: the uniform double-layer model. The properties of this model are contrasted to those of other distributed source models from the perspective of their inherent capacity for imposing the constraints that are essential for regularizing the involved inverse problem.