Abstract
Pacing threshold, epicardial R-wave amplitude and pacing impedance in sixteen ELC 54 (Biotronik) epicardial fractally coated screw-in leads were regularly measured over a period of 18 months and compared with two control groups: 1.with conventional epicardial non-fractal Pt-fr screw-in leads (n = 16), and 2.with endocardial fractally coated fr leads (n = 14). The ELC 54 leads exhibited markedly lower pacing thresholds than the conventional non-fractal control group; this difference was significant at the 12th month after implant (t-test, p = 0.0392).
Pacing thresholds in the ELC 54 lead were significantly higher (p<0.05) than those in the endocardial fractal control group, as expected, maintaining their maximum even in the 3rd month after implant. Therefore, a pacemaker energy output in the ELC 54 lead should be reduced later (from the 3rd to the 6th month after insertion) than in endocardial leads.
A low pacing impedance observed in the ELC 54 in chronic stage (below 400 U) seems to be a drawback because it additionally increases the current drain of a pacemaker.