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Do Electrode and Lead Design Differences for Permanent Cardiac Pacing Translate into Clinically Demonstrable Differences? (Comparison of Sintered Platinum and Activated Vitreous and Porous Carbon Electrodes)

A randomized prospective study was undertaken to compare the electrical performances of three permanent, endocardial, tined pacing leads with different electrode designs—sintered platinum, vitreous carbon, and porous carbon. Ninety‐nine patients received one of the leads (S80 31; 423S 32; S100 36). Acute R wave amplitude and ST elevation of ihe native endocardiai electrogram, voltage threshold, impedance, and current flow at four pulse durations (0.25–1.0 msec) were measured. Voltage thresholds were measured noninvasively at each of four pulse durations at 2 days and 1, 3, and 6 months after implantation. No significant differences were found in sensing properties, or current flow at threshold at 0.5 msec pulse duration. The 423S lead had a significantly higher impedance at threshold and both a higher impedance and lower current flow at 5 V. No significant differences in threshold voltages were found between the three leads at any pulse duration, at any of the assessed times after implantation. Six‐month thresholds for the S80, 423S, and S100 leads were 1.18 ± 0.35, 1.17 ± 0.29, and 1.06 ± 0.38 V respectively at 0.5 msec pulse duration. Differences between ‘high performance’ pacing leads need to be of a greater order of magnitude before they can be exploited to give any real clinicai advantage to patients.