title: Long-term thresholds of nonsteroidal permanent pacing leads: a 5-year study.
abstract: The present commercial market supports many nonsteroidal endocardial pacing leads of differing construction. In order to compare the performance of these configurations, we studied the long-term pacing properties of three representative lead types by randomized clinical trial in 99 patients undergoing a first elective VVI implant. Thirty-one patients received sintered platinum leads, 36 activated pyrolytic carbon leads, and 32 vitreous carbon leads. All received generators capable of noninvasive threshold testing. Acute sensing parameters were R wave amplitude and ST segment elevation measured from the endocardial electrogram. Noninvasive voltage thresholds were measured at implantation, 2 days, 1, 3, and 6 months, and yearly thereafter for 5 years. There were no significant differences between leads in pacing or sensing capabilities at implantation. All three demonstrated similar increases in thresholds, peaking at 1 month, then falling to a plateau by 6 months and did not vary significantly thereafter. There were no significant differences in thresholds between leads during 5 years of follow-up. The lowest mean threshold at 5 years was 0.93 V at 0.5 ms. This study suggests that: (1) although these lead types all perform well, none offers any particular clinical advantage over another; (2) the degree of early threshold peaking precludes immediate postimplant output reduction, but later thresholds are sufficiently low to enable reductions in pacing output; (3) safe low energy pacing requires greater attention to the lead-generator combinations; (4) data obtained at subsequent annual follow-up provided no additional useful clinical information to that obtained at 1 year; and (5) in the absence of other differences, cost can be the deciding factor in lead selection.
authors: Cardiothoracic Centre, Freeman Hospital, Newcastle upon Tyne, United Kingdom.
authors: T P
authors: TP
authors: Gumbrielle
authors: J P
authors: JP
authors: Bourke
authors: M
authors: M
authors: Sinkovic
authors: M
authors: M
authors: Tynan
authors: P
authors: P
authors: Kittpawong
authors: R G
authors: RG
authors: Gold
mesh_terms: D000368:Aged; D001672:Biocompatible Materials / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D003365:Costs and Cost Analysis; D004553:Electric Conductivity; D011211:Electric Power Supplies; D004562:Electrocardiography; D004567:Electrodes, Implanted / Q000191:economics; D004867:Equipment Design; D004869:Equipment Safety; D005260:Female; D005500:Follow-Up Studies; D006358:Hot Temperature; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D010138:Pacemaker, Artificial / Q000191:economics; D010984:Platinum / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; C009139:pyrolytic carbon; D010984:Platinum; D002244:Carbon