title: Long-term performance of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead.
abstract: Bipolar epicardial leads are not yet widely available for atrial use. Since September 1986, we have used a bipolar active fixation endocardial lead (Cardiac Pacemakers model number's 4266, 4268, and 4269) as a bipolar epicardial atrial lead by attaching the corkscrew tip to the atrial surface and imbricating atrial tissue around the more proximal electrode. A total of 77 bipolar epicardial atrial leads have been implanted using this approach in 72 patients with congenital heart disease (ages 3 months to 38.7 years; mean 8.9 +/- 8.8 years). Indications for atrial pacing included AV block (n = 46), sinus node dysfunction (n = 17), and antitachycardial pacing (n = 9). Indications for epicardial pacing included the presence of an intracardiac right to left shunt (n = 33), concomitant cardiac surgery (n = 26), surgeon preference (n = 7), and lack of transvenous access to the atrial endocardium (n = 6). Follow-up (median 23 months; mean 28.0 +/- 23.1 months; range 1-78 months) data beyond 1 month postimplantation were available for 44 leads. Atrial sensing was > or = 2.0 mV for 26 leads (59%) with sensing possible at > or = 0.75 mV for 42 leads (95%). Threshold data were available at 5 V for 37 leads and at 2.5 V for 36 leads with mean pulse width thresholds measuring 0.21 +/- 0.33 ms and 0.34 +/- 0.34 ms, respectively. Two leads failed (high capture thresholds at 5 days [n = 1], lead fracture at 42 months [n = 1]; one of which was replaced. Four additional leads were replaced electively (marginal thresholds [n = 1], intermittent phrenic nerve stimulation [n = 1], damaged during subsequent surgery [n = 1], clinically irrelevant insulation break [n = 1]) concomitant with additional cardiac surgery. Until a commercially available lead is developed and released, improvisation with a bipolar active fixation endocardial lead as a bipolar epicardial atrial lead is a reasonable approach to providing bipolar atrial sensing and pacing in patients for whom endocardial pacing is contraindicated.
authors.affiliation: Children's Hospital, Department of Cardiology, Boston, Massachusetts 02115, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Epstein
authors.forename: E P
authors.initials: EP
authors.lastname: Walsh
authors.forename: J P
authors.initials: JP
authors.lastname: Saul
authors.forename: J K
authors.initials: JK
authors.lastname: Triedman
authors.forename: J E
authors.initials: JE
authors.lastname: Mayer
authors.forename: W J
authors.initials: WJ
authors.lastname: Gamble
mesh_terms: D000293:Adolescent; D000328:Adult; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D004567:Electrodes, Implanted; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D006325:Heart Atria; D006330:Heart Defects, Congenital / Q000628:therapy*; D006801:Humans; D007223:Infant; D008297:Male; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D016019:Survival Analysis