Vector mapping of three-dimensionally reconstructed intrabody organs and method of display

Apparatus for representing the state of a heart, comprising: a) a processor for creating a map of an area of ​​the heart; b) a catheter comprising a functional portion for measuring a physiological response at at least three sampled points on the surface of the heart; c) a processor for calculating a vector function derived from a set of scalar measurements of a surface of the heart, related to said response; d) means for displaying a representation of said vector function and said physiological response on said map, wherein said vector function is represented as an arrow and said physiological response is represented as a map of pseudocolores.