Cardiac excitation generates an electric field which projects onto the body surface. This allows the information about the heart to be obtained noninvasively as a physical process. Thus the analysis of the cardioelectric field requires spatial, spatio-temporal and temporal approaches. The spatial approach resolves the distribution of the field in the body in relation to the configuration of the source by means of constructing a field map for one instant. This reflects the anatomical background. The spatio-temporal analysis includes the events of activation and repolarization, provides a series of maps or compressed presentations and comprises the dynamics of the cardiac excitatory cycle. The temporal access investigates the generation of the cardiac rhythm. It utilizes the analysis of sinus arrhythmia and the frequency analysis of heart rate variability. The results reflect efferent mechanism of chronotropic control as well as afferent and central management of informations relevant for cardiac control.