1. A computer-implemented method for visualizing physiological data of a patient, the method comprising: storing in memory electroanatomic data representing electrical activity for a predetermined surface region of the patient; providing an interactive graphical representation of the predetermined surface region of the patient; receiving a user input that defines location data corresponding to a user-selected location for at least one roving virtual electrode on the graphical representation of the predetermined surface region of the patient; and dynamically generating a graphical representation of the physiological data corresponding to a current location of the roving virtual electrode relative to the graphical representation of the predetermined surface region of the patient, such that the graphical representation of the physiological data is modified continuously responsive to changes in the current location of the roving virtual electrode as the roving virtual electrode is moved.