Abstract
Threshold elevation was observed in the pacing electrode within the seven to ten days after implantation. We studied whether the threshold elevation would be mitigated when steroid was made eluting from the surface of the glassy carbon electrode.At first, we dipped the electrode into the mixture of dimethyl silicon oil and dexamethasone sodium phosphate (DSP) powder, just before electrode insertion. This method was not so effective. Secondly, we made four drilling holes of 300 μm in diameter in the surface of the glassy carbon electrode, and filled silicon gel in them mixed with DSP. With this method, threshold elevation was effectively suppressed at the 7th post operative day compared with the steroid non-eluting control electrode of the same design, either in the atrial or ventricular pacing. Energy threshold was successfully lower in the steroid eluting glassy carbon electrode (DS58V) when compared with commercially available Capsure 4003 electrode. However, at 10 months, there was no difference in threshold between the steroid eluting and non-eluting DS-58V electrode.
