Electrochemistry of after-pacing potentials on electrodes.

Predictable electrochemical behavior of electrodes in physiologic pacemakers is desirable. The after-pacing potentials play a major role in determining precise sensing and pacing performance between both chambers. Ideally, pacemaker input impedance should be high (in relation to the electrode/blood interface), whereas the potential remaining on the electrode should be as low as possible. Both of these conditions are influenced by the electrode material, structure, and design. Results of in vivo and in vitro testing show that the after-pacing potential interference is directly related to the potential decay, and these values are in general considerably shorter than the blanking periods.