Abstract: This pacing system relates to a rate varying cardiac pacemaker (1) for electrically stimulating the heart of a pacemaker wearer. The electrical cardiogenic heart depolarization is detected on a multipolar single probe with the aid of individual electrodes (7 to 10). Bipolar electrodes in the atrium allows for detection of the intra-atrial actions (P-wave) as a first rate control signal for controlling the pacemaker in the atrially triggered ventricular pacing mode (VDD). A second rate control signal other than the P-wave correlating with patient activity is determined in parallel with the P-wave control signal. The two control signals are compared to decide if the intra atrial actions (P-waves) are appropriate control signals. Pace rate control is switched between the two signals in order to produce the most beneficial pacing mode to the patient, for example, VDD or VVI rate responsive modes.

Abstract: This invention has as an objective the universal matching of individual patient-pacemaker-implant electrode interface conditions to follow dynamic changes occurring in use, from pacemaker to pacemaker and from patient to patient to control the pacing pulse energy in operation most efficiently to prolong battery life. Information from the implanted stimulation electrode is analyzed to discriminate the energy level of pulses effective and ineffective to stimulate a heartbeat for at least two different stimulation pulse characteristics. This analyzed information is automatically processed in logic circuits to conform with the requirements of particular pacemaker adjustments to develop an optimized energy pacing pulse with adequate safety margin. Programming and logic equipment can be in the pacemaker, but additional energy saving with those calculations takes place when it is external to the pacemaker and bidirectional communication of information takes place with the pacemaker.