Measurement of pacemaker performance

Abstract

Entirely satisfactory treatment of complete heart block has been prevented by an inability to measure pacemaker function after implantation. Two major problems can be identified in the long-term management of pacemaker patients: first, adequate prediction of when a pacemaker will fail; and second, accurate diagnosis of the type of pacemaker failure if it occurs.Observations on dogs gave precise measurements of interelectrode impedances. A method is described of externally measuring the interelectrode resistance and capacitance of implanted pacemakers. In studies on both dogs and human beings it was found that all changes in interelectrode impedance could be identified by changes in pacemaker rate and pulse width. Serial measurements of these two parameters allowed accurate diagnosis of the different types of "pacemaker failures." The method also enabled anticipation of failures, other than wire breakage, before they were clinically evident. We think that pacemaker performance can be adequately evaluated by this method, making unnecessary prophylactic replacement of the unit.