Body surface Laplacian electrocardiographic mapping--a review.

It is of great importance and significance to be able to noninvasively map spatially distributed cardiac electrical activity from body surface electrical recordings. The standard electrocardiographic monitoring techniques provide little spatial information regarding cardiac electrical activity. Recently, a new approach-body surface Laplacian electrocardiographic mapping-has been aggressively pursued to provide high-resolution spatial mapping of cardiac electrical activity. The fundamental innovation is the measurement of the Laplacian electrocardiogram distribution over the body surface. The body surface Laplacian electrocardiographic maps have been shown to provide enhanced ability to map multiple spatially separate cardiac bioelectric sources. This article reviews the theoretical and experimental aspects of this emerging mapping technique. First of all, the paper briefly reviews the historical development of body surface mapping and inverse solutions for mapping the distributed cardiac electrical activity. Then the paper reviews the theoretical basis of body surface Laplacian mapping and the biophysical interpretation of body surface Laplacian signals, as well as technical consideration of the Laplacian recording and instrumentation. Investigations of body surface Laplacian maps in computer models and a physical tank model, as well as physiological studies are also reviewed.