An electrophysiology system for mapping tissue includes a catheter having a plurality of electrodes. The system may be a catheter having a dense collection of small electrodes on its tip. The electrodes may be arranged in a pattern that is constant regardless of rotational orientation. The system may be an electrophysiology apparatus having a catheter, the catheter having a body with a proximal end and a distal end. At the distal end of the catheter body is a distal tip comprising a plurality of electrodes and/or coaxtrodes. A signal processor may be operably connected to the plurality of electrodes and/or coaxtrodes and can measure at least one electrophysiological parameter.
