Cross‐Talk in Bipolar Pacemakers

Abstract

Investigation of dual chamber pacing and sensing interactions at high rates is becoming increasingly important with the advent of sensor driven dual chamber pacemakers. The present study was designed to investigate the pacemaker and lead interactions that will affect cross-talk during high rate atrial and ventricular pacing. The study was divided into two phases, phase one investigated the mechanisms of cross-talk using standard pacemaker circuitry and various electrode types in a canine model. In six dogs with complete heart block, dual chamber pacing was carried out with four lead types at increasing pacing rates, while output of the ventricular sense amplifier of a pacemaker breadboard was monitored. Ventricular sense amplifier output signals (n = 332) progressively increased from 31.5 +/- 18.3 mV at 100 ppm to 102 +/- 55 mV at 160 ppm. Smooth platinum-iridium and platinized leads were statistically different at higher pacing rates (P less than 0.05). This signal level is sufficient to lead to a ventricular sensing event. In a second phase of the study, the incidence of cross-talk at high pacing rates was studied in patients with implantable dual chamber bipolar pacemakers. In 166 clinical trials on 106 patients with the same pacemaker, there was evidence of cross-talk in 1/59 cases at 110 ppm and 3/47 at 130 ppm, but none at higher rates.(ABSTRACT TRUNCATED AT 250 WORDS)