Assessment of long-term stability of chronic ventricular pacing thresholds in steroid-eluting electrodes.
Sixteen patients with Medtronic 4003 steroid-eluting electrodes implanted in the ventricular position were followed over 5 years. In each patient a special type of Medtronic 2443 pacemaker was implanted to allow programming of output at 1.35 V. Chronic threshold values in these patients measured at an output of 1.35 V were stable over the first 18 months of follow-up. Mean values were: 0.06 +/- 0.03 msec at 6 months and 0.08 +/- 0.02 msec at 18 months; these did not differ from each other significantly. However, during the period from 18 to 36 months postimplantation, a significant increase in mean pacing threshold was observed: 0.08 +/- 0.02 msec at 18 months postimplantation versus 0.14 +/- 0.05 msec at 36 months (P < 0.01). After 36 months, the chronic pacing threshold remained stable until the end of the 5-year follow-up period. Further long-term study of chronic threshold behavior of steroid-eluting electrodes measured at low amplitudes is warranted.
Stojanov
P
P
Pacemaker Center, University Clinical Center, Belgrade, Yugoslavia.
Djordjević
M
M
Velimirović
D
D
Belkić
K
K
D002304:Cardiac Pacing, Artificial / Q000379:methods; D003907:Dexamethasone / Q000031:analogs & derivatives*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000453:epidemiology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012804:Sick Sinus Syndrome / Q000453:epidemiology / Q000628:therapy; D013997:Time Factors
C004180:dexamethasone 21-phosphate; D003907:Dexamethasone