A system for presenting information representative of patient electrophysiological activity, such as complex fractionated electrogram information, includes at least one electrode to measure electrogram information from the heart surface, at least one processor coupled to the at least one electrode to receive the electrogram information and measure a location of the at least one electrode within the heart, and a presentation device to present the electrogram information as associated with the location at which it was measured on a model of the patient's heart. A memory may also be provided in which to store the associated electrogram information and measured location. Data may be analyzed using both time-domain and frequency-domain information to create a three-dimensional map. The map displays the data as colors, shades of color, and/or grayscales, and may further utilize contour lines, such as isochrones, to present the information.