Do electrode and lead design differences for permanent cardiac pacing translate into clinically demonstrable differences? (Comparison of sintered platinum and activated vitreous and porous carbon electrodes).
A randomized prospective study was undertaken to compare the electrical performances of three permanent, endocardial, tined pacing leads with different electrode designs--sintered platinum, vitreous carbon, and porous carbon. Ninety-nine patients received one of the leads (S80 31; 423S 32; S100 36). Acute R wave amplitude and ST elevation of the native endocardial electrogram, voltage threshold, impedance, and current flow at four pulse durations (0.25-1.0 msec) were measured. Voltage thresholds were measured noninvasively at each of four pulse durations at 2 days and 1, 3, and 6 months after implantation. No significant differences were found in sensing properties, or current flow at threshold at 0.5 msec pulse duration. The 423S lead had a significantly higher impedance at threshold and both a higher impedance and lower current flow at 5 V. No significant differences in threshold voltages were found between the three leads at any pulse duration, at any of the assessed times after implantation. Six-month thresholds for the S80, 423S, and S100 leads were 1.18 +/- 0.35, 1.17 +/- 0.29, and 1.06 +/- 0.38 V respectively at 0.5 msec pulse duration. Differences between 'high performance' pacing leads need to be of a greater order of magnitude before they can be exploited to give any real clinical advantage to patients.
Bourke
J P
JP
University Department of Cardiology, Freeman Hospital, Newcastle-Upon-Tyne, U.K.
Howell
L
L
Murray
A
A
Hill
W E
WE
Cowan
J C
JC
Beatt
K
K
Errington
J
J
Jameson
S
S
Gold
R G
RG
D000368:Aged; D000369:Aged, 80 and over; D002244:Carbon; D002986:Clinical Trials as Topic; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D010984:Platinum; D011897:Random Allocation
D010984:Platinum; D002244:Carbon