An
electrophysiology apparatus is used to measure electrical activity occurring in a heart of a patient and to visualize the electrical activity and / or information related to the electrical activity. A three-dimensional map of the electrical activity and / or the information related to the electrical activity is created. Exemplary maps include a
time difference between action potentials at a roving
electrode and a
reference electrode, the peak-to-peak timing of action potentials at the roving
electrode, the peak
negative voltage of action potentials at the roving
electrode, complex fractionated electrogram information, a
dominant frequency of an electrogram
signal, a maximum peak amplitude at the
dominant frequency, a ratio of energy in one band of the frequency-domain to the energy in a second band of the frequency-domain, a low-frequency or high-frequency
passband of interest, a frequency with the maximum energy in a
passband, a number of peaks within a
passband, an energy, power, and / or area in each peak, a ratio of energy and / or area in each peak to that in another passband, and a width of each peak in a spectrum. Colors, shades of colors, and / or grayscales are assigned to values of the parameters and colors corresponding to the parameters for the electrograms sampled by the electrodes are updated on the three-dimensional model.