Pacemaker Automaticity: Real Progress or Increased Complexity and Costs?

Abstract

Pacemaker automaticity may be defined as the “algorithmic regulation of pacer function based on patient conditions and pacemaker system conditions without the need for clinician input” [1]. Indeed, it does not represent a new concept. More than twenty years ago the “autodiagnostic pacemaker” was described as a device capable of detecting failure to capture and failure to sense, allowing for automatic adjustment of output voltage [2]. Demand pacing automatically adjusts and resets pacemaker timing based on endogenous rhythm. Pulse width stretching was an old concept whereby the pacemaker attempted to maintain constant energy: as battery voltage depleted, the pulse generator would increase pulse width so as to maintain a margin of safety relative to stimulation thresholds. “Regulated outputs” use regulator circuitry for the output voltage of pacing pulses to compensate for gradually decreasing battery voltage. Unipolar systems automatically reverted to asynchronous pacing when myopotentials were sensed so as to prevent undue inhibition of pacer output. “Power on reset” and related approaches allowed for the automatic detection of electromagnetic interference such as electrocautery and set the pacemaker to predetermined settings to prevent unintended setting of parameters by severe interference.