[Modern electrodes with and without steroid: effects on stimulation current of cardiac pacemakers]

The aim of the investigation was to test whether new leads without steroid, a meshwire tip leads (Ionyx 4180, CPI; n = 10) and a carbon tip lead (Facet ITP 13, Vitatron; n = 10), have electrical characteristics similar to a new steroid-eluting tip lead (CapSure SP 4023, Medtronic; n = 10) and their impact on the pacemaker's pacing current. Pacing thresholds, impedance, and R-wave amplitudes measured at implantation were similar for the three leads. One, 4 and 12 weeks after implantation both nonsteroid leads had significantly higher pacing thresholds at 0.1 and 0.3 ms pulse duration in comparison to the steroid lead (after 12 weeks at 0.3 ms steroid: 0.9 +/- 0.2 V, carbon: 2.1 +/- 0.5 V; meshwire: 1.5 +/- 0.5 V). This result was restricted to the carbon lead after 52 weeks. At 0.5 ms pulse duration higher pacing thresholds were obtained for the carbon lead (after 12 weeks at 0.5 ms; steroid: 0.8 V, carbon: 1.7 +/- 0.6 V; meshwire: 1.1 +/- 0.4 V). Impedance of the steroid lead was 531 +/- 61 ohms, 535 +/- 54 ohms, and 511 +/- 50 ohms, respectively, after 4, 12, and 52 weeks, whereas the carbon lead had significantly higher values with 652 +/- 84 ohms, 669 +/- 93 ohms, and 657 +/- 107 ohms, respectively. The impedance of the meshwired lead (4 weeks: 585 +/- 92 ohms; 12 weeks: 592 +/- 89 ohms; 52 weeks: 550 +/- 130 ohms) did not differ from the steroid lead.(ABSTRACT TRUNCATED AT 250 WORDS)