Long-term assessment of unipolar and bipolar stimulation and sensing thresholds using a lead configuration programmable pacemaker

Acute and long-term pacing thresholds were measured prospectively in 74 patients with a unipolar/bipolar mul-tiprogrammable pacemaker. At implantation, mean current threshold was 0.48 ± 0.16 mA with unipolar mode and 0.55 ± 0.16 mA bipolar mode (p < 0.01). R wave amplitude at implantation was 7.78 ± 2.4 mV with unipolar and 7.67 ± 2.1 mV in bipolar mode (p = NS). During long-term follow-up (mean 9.3 months; range 3 to 24), no clinically significant differences in pacing or sensing thresholds were observed between bipolar and unipolar configurations.