Following our preliminary studies which have shown that an automated real-time measurement of the electrophysiologic intervals is feasible, we are now developing a new instrument, which integrates programmable cardiac pacing and response analysis due to a multiprocessor system. The system dtects the atrial, His, and ventricular waves and measures beat to beat the time intervals between them. Measurements have been made during 40 clinical studies randomly chosen from about 700 and including different conditions like sinus rhythm, acute drug tests and programmed atrial pacing. Examples of automatic analysis performed during the execution of the protocols for the measure of Wehckebach frequency and sinus node recovery time are reported.