A system and method for assessing effective delivery of ablation therapy to a tissue in a body is provided. A three-dimensional anatomical map of the tissue is generated and displayed with the map defining a corresponding volume. An index is generated corresponding to a location within the volume with the index indicative of a state of ablation therapy at the location. The index may be derived from one or more factors such as the duration an ablation electrode is present at the location, the amount of energy provided, the degree of electrical coupling between an ablation electrode and the tissue at the location and temperature. A visual characteristic (e.g., color intensity) of a portion of the anatomical map corresponding to the location is then altered responsive to the index.