Long-term results of high vs. normal impedance ventricular leads on actual (Real-Life) pacemaker generator longevity

The long-term effects of high impedance vs. standard impedance pacing leads on actual generator longevity were studied. In 40 patients (21 females, age 73 +/- 13 years) with standard dual-chamber pacemaker indication, bipolar standard impedance ventricular leads and high-impedance leads were implanted in a randomized fashion. Identical pacemaker generators and atrial pacing leads were implanted in all patients. Patients were observed during a mean follow-up of 89.8 +/- 8.8 months before pacemaker replacement. Initially, the patients who received the high-impedance leads had a lower current drain as compared with standard pacing impedance leads, and the estimated pacemaker longevity was significantly prolonged, too. But this pattern disappeared after 6 years of follow-up, and finally the actual pacemaker generators' replacement time was 86.7 +/- 6.8 months in standard impedance lead group vs. 91.2 +/- 10.3 months in high-impedance lead group (P = 0.17). Implantation of high pacing impedance leads for ventricular stimulation does not result in a benefit with respect to pacemaker longevity as compared with standard impedance leads.