Acute and long-term atrial and ventricular stimulation thresholds with a steroid-eluting electrode

Thirty leads with a steroid-eluting electrode (Medtronic 4003 and 4503) have been implanted in 24 patients, 11 in the atrium and 19 in the ventricle. Six patients received the steroid lead in both atrium and ventricle. The stimulation thresholds were followed using Elema pulse generators with Vario function in 15 patients (11 atrial leads and 10 ventricular leads) during 11 +/- 3 months (mean +/- SD). At 0.5 ms pulse duration the mean atrial and ventricular thresholds were 0.55 Volt +/- 0.22 and 0.39 Volt +/- 0.22 respectively at implant, 0.94 Volt +/- 0.13 and 0.82 Volt +/- 0.16 after 12 months. During the entire follow-up period both atrial and ventricular mean thresholds never exceeded 1 V.