Reduction of the pace polarization artefact for capture detection applications by a tri-phasic stimulation pulse

Abstract

This study investigated the ability to minimize pace polarization artefacts (PPA) by adjusting the post-stimulus pulse duration of a tri-phasic stimulation pulse. Adjustment of the stimulation pulse was enabled by downloading special study software into an already implanted pacemaker. Tests were performed in a total of 296 atrial leads and 311 ventricular leads. Both chronic and acute leads were included in the study. Statistically significant differences were found in the initial PPA (without any adjustment of the stimulus pulse) between atrial and ventricular leads. In addition, significant differences were observed among various lead models with respect to changes over time in the initial ventricular PPA. Successful PPA reduction was defined as a reduction of the PPA below 0.5 mV for atrial leads and below 1 mV for ventricular leads. Results show a success rate for ventricular and atrial PPA reduction of 97.8% and 98.7%, respectively. Threshold tests showed that after reduction of the PPA loss of ventricular capture can be reliably detected. However, atrial threshold tests showed many false positive evoked response detections. In addition, unexpectedly high evoked response amplitudes were observed in the atrium after reduction of the PPA. Results from additional measurements suggest that these high atrial evoked response amplitudes come from the influence of the input filter of the pacemaker.

Effect of Atrial Lead Position on Atrial Automatic Capture Verification

“…The ability to reduce or eliminate the pacing‐induced afterpotential or ART that occurs simultaneously with the AER would significantly improve the ability of the pacemaker to determine atrial capture. Several technologies have been tested to reduce the ART including reduction of polarization voltage by electrode coatings (TiN, platinum black, and iridium oxide), 5,6 use of various triphasic stimulation waveforms, 11,12 and reduction of coupling capacitance 7 . Unfortunately, all of these methods have proven to have their own unsatisfactory limitations including the potential to increase demand on pulse generator battery as this is associated with triphasic stimulation.…”