A system and method for identifying and treating a source of a heart rhythm disorder are provided in which a spatial element associated with a region of the heart is selected. Progressive rotational activations or progressive focal activations are determined in relation to the selected spatial element. A plurality of indexes of progressive rotational activations or progressive focal activations over time is formed. One or more indexes are selected from the plurality of indexes that indicate consistency of the successive rotational activations or the progressive focal activations in relation to a portion of the region of the heart.