Specific software for the analysis of the recorded signals specially designed for the available mapping systems. In the phase of acquisition of the electrical signals during the experiments, and in the subsequent processing and analysis of the data obtained, two working environments are basically used. On the one hand, the PaceMap software (Waalre, The Netherlands) incorporated in the MapTech acquisition system and, on the other hand, MatLab (Mathworks Inc., Natick, MA, USA) specific programmes for which the necessary codes were developed to extract the information from the records. PaceMap is therefore the software of the cardiac mapping system used in the capture and analysis of electrograms in the experiments and runs under the Windows operating system (Microsoft, Redmond, WA, USA). It performs the acquisition configuration functions, allowing the change of gain, sampling rate and control of the recordings.