A New Steroid-Eluting Low Threshold Pacemaker Lead
1983; Linguagem: Inglês
10.1007/978-3-642-72367-4_54
AutoresGERALD C. TIMMIS, Seymour Gordon, Douglas C. Westveer, James R. Stewart, Ken Stokes, John Helland,
Tópico(s)Conducting polymers and applications
ResumoAnimal studies have shown that dexamethasone sodium phosphate eluting from a silicone core through a porous electrode at focal megadose levels preferentially lowers ventricular thresholds compared with control leads having conventional and porous electrodes. A similar unipolar tined lead with a porous 8 mm2 hemispherical electrode attached to a silicone core impregnated with ≤ 1 mg of dexamethasone sodium phosphate was implanted in 18 patients with a special low output generator. Serial thresholds (µJoules) measured at 1.3 5 volts (0.391 ±.03 (mean ± SEM)) at implant, 1582 ±.07 at one week, and 0.795 ± 0.07 at 12 weeks) were lower than equivalent values in five control patients with the same generator but with conventional (6971) leads (p <.001). Telemetered R waves were higher throughout the study period than in controls (p < 0.005). These data are in contrast with previous noninvasive tracking studies in this laboratory showing threshold peaking or loss of capture at nominal outputs, within 40 days of implant, in 30% of patients with conventional pacing systems emitting voltages two to four times as high. In conclusion, a new corticosteroideluting lead has been shown to produce very low and stable thresholds which are significantly better than those seen with conventional leads for up to 12 weeks. Better sensing was also observed over the same period. The mechanism of steroid effect which lasts well beyond the period of elution is unknown but may be anti-inflammatory at the electrode-tissue interface.
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