Initial Results with an Activated Pyrolytic Carbon Tip Electrode

Abstract

The initial results acquired from testing of a new activated pyrocarbon electrode for cardiac pacing are presented. In vitro testing has shown energy efficiency to be higher than for platinum electrodes. Histologic examination of implanted leads in animals has demonstrated a less significant tissue reaction at the tip. Finally, in a clinical trial of 121 patients with these leads, strength-duration curves have low rheobase values. Chronic thresholds are often consistently low. These reports suggest very satisfactory results with this pyrolytic carbon electrode.

The Electrode‐Tissue Interface: The Revolutionary Role of Steroid‐Elution

“…This process resulted in a very fine microtexture. In general, activated carbon electrodes resulted in acceptable stimulation thresholds …”

“…D, C, and 8C) . In Europe and to a lesser extent in the United States, textured carbon had been used as a cathode material because of its acceptable stimulation thresholds and relatively low polarization properties . Ordinary carbon or graphite is mechanically weak, brittle, and has poor wear resistance.…”

“…It had earlier been argued that for some electrodes, steroid‐elution was not necessary as comparable chronic data could be presented with electrodes composed of microporous carbon, platinized porous‐platinum, titanium nitride, or iridium‐oxide‐coated titanium electrodes without steroid . However, it is now recognized that all electrodes without steroid‐elution can develop an unpredictable acute “peaking” in the stimulation threshold, which can last for several months and in some cases progress to complete and chronic exit block, making it necessary to program pulse generators at implantation to high energy outputs to ensure an adequate margin of safety.…”