1. A method for diagnosing and treating pathologies in a heart, the method comprising: using a system including a mapping probe and a processing system for: sensing activation signals of physiological activity in the heart with the mapping probe including a plurality of mapping electrodes disposed in the heart, each of the plurality of mapping electrodes having an electrode location; identifying patterns among the sensed activation signals representing activation propagation; generating a similarity measure between each unique pair of identified patterns; classifying the patterns into groups based on the similarity measure; determining a plurality of characteristic representations, each of the plurality of characteristic representations corresponding to a unique one of the groups and comprising a single numerical representation that summarizes the patterns in the corresponding group; and displaying at least one of the plurality of characteristic representations to aid in visualization; identifying at least one site in the heart having a pathology based on the at least one of the plurality of characteristic representations displayed; and treating myocardial tissue at or near the at least one site in the heart to treat the pathology.