Display and analysis of three dimensional experimental electrocardiographic data

The fundamental problem of electrocardiography is to interpret body surface voltage distributions induced by cardiac generated currents. As a step towards understanding this process further, experimental potential data were collected from 600 electrode sites on and within a tank of electrolyte in which an isolated, perfused, canine heart was immersed. Programs were written to display potentials in horizontal, vertical, and circular formats. Studies on the effect of distance from the source to surfaces in the volume were carried out through the use of eigenvector analysis. Through use of a cross covariance transformation, analysis of the ability to represent data on one surface by the eigenvectors of another surface was conducted. Results include development of programs to display and analyze data from three dimensional electrode arrays in two dimensional graphical formats. Results from the studies of distance effects include analysis of the information content of the primary eigenvectors and their associated eigenvalues. It was found that the error could be decreased from 20 percent to 12 percent by increasing the number of eigenvalues used to recreate the surface from 3 to 5.