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Benefits of Smaller Electrode Surface Area (4 mm 2 ) on Steroid‐Eluting Leads
Author(s) -
SCHUCHERT ANDREAS,
KUCK KARLHEINZ
Publication year - 1991
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1991.tb06480.x
Subject(s) - ohm , electrode , medicine , pulse (music) , lead (geology) , electrical impedance , implant , biomedical engineering , materials science , surgery , electrical engineering , voltage , chemistry , geomorphology , geology , engineering
The purpose was to test whether a reduction of pacemaker electrode surface area below 8 mm 2 improves leads that elute steroid from the electrode tip to the surrounding myocardium. A standard‐sized 8 mm 2 lead with 1 mg dexamethasone was implanted in 12 patients and a lead with 4 mm 2 electrode surface area and 0.5 mg dexamethasone in ten patients. Pacing threshold, impedance, and sensing threshold were measured at implantation and after 1, 4, and 12 weeks. Pacing thresholds were similar for both groups and were always ± 0.8 V at 0,5 msec pulse duration in all patients. Impedance was significantly higher (P < 0.05) for the 4 mm 2 lead (implantation: 726 ± 119 ohms; 1 week: 596 ± 71 ohms; 4 weeks: 624 ± 68 ohms; 12 weeks: 643 ± 56 ohms) than for the 8 mm 2 lead (implantation: 422 ± 43 ohms; 1 week: 402 ± 48 ohms; 4 weeks: 439 ± 57 ohms; 12 weeks: 449 ± 61 ohms). R wave amplitudes did not differ between both groups; no sensing failure occurred at 5 mV sensitivity. Compared to the 8 mm 2 lead the reduction of surface area to 4 mm 2 did not influence pacing threshold, but resulted in a higher pacing impedance. The amount of pacing energy was lower in the smaller‐sized electrode. For clinical impact, low pacing threshold and high impedance leads are the condition to implant pulse generators with smaller battery capacity.