Sensing characteristics of the right atrial appendage electrode.

In order to explore fully the sensing characteristics of both bipolar and unipolar configurations of the tined right atrial appendage electrode, detailed electrographic analysis was performed in 10 patients undergoing atrial electrode implantation. Though no differences were noted between unipolar and bipolar atrial deflections in electrograms from these leads, the unipolar ventricular deflections were greater in both amplitude (1.9 vs 0.6 mV) and slew rate (0.17 vs 0.07). These data suggest that bipolar pacing configurations might be preferable when selective atrial sensing is important.