Abstract
Permanent steroid eluting leads are used for the purpose of lowering stimulation threshold elevation due to foreign body reaction. To evaluate the eluting capabilities, a single electrode was placed into a test tube containing 1.0ml of distilled water. After 60 minutes, the lead was taken out of the test tube and the solution was removed for analysis of steroid. Then an another test tube containing 1.0ml of distilled water was prepared and the lead was placed again into the water and waited for the next 120 minutes. These procedures were continued periodically. Analysis of dexamethason sodium phosphate(DSP) was performed by high performance liquid chromatography (HPLC). The highest concentration of DSP was obtained at the first 60 minutes interval in the CAPSURE lead. But during the next 20 hours interval, the SELUTE and the ENCORDEC lead showed much more DSP elution. The DS58V steroid eluting lead which was produced in our institute had 4 holes in the electrode surface and was filled with a mixture of silicon gel and DSPat our institute. In order to slow the rate of steroid elution over time and lengthen the effect of steroid against the myocardium, various kinds of carbon powder were tested adding to the DSP silicon gel complex. DSP silicon gel with activated graphite powder resulted in the best suitable electrode for modification of the eluting capabilities which would inhibit the peaking of the stimulation threshold on the 7th to 10th day after implantation.
