Catheter ablation has become the treatment of choice for many types of arrhythmias largely because it is curative, safe, and relatively inexpensive. However, the catheter based mapping techniques used to determine the target sites for ablation still need further development. The overall goal of this research is development of a novel system for endocardial mapping; one that will present endocardial activation patterns in an intuitive manner that leads to rapid interpretation by the clinician, while preserving the detailed information necessary for diagnostic purposes. This system will provide clinicians with a powerful, real-time tool that will assist them in interpreting the large volume of information acquired during endocardial mapping procedures. Data processing will take place in moments rather than minutes, in plenty of time for the clinician to act on the content of the data.