title: Experience with a low profile bipolar, active fixation pacing lead in pediatric patients.
abstract: Continued miniaturization of permanent pacing systems has promoted use of this technology in younger and smaller pediatric patients. Intermedics ThinLine 438-10 active fixation pacing leads (4.5 Fr lead body) were implanted in 26 patients (17 males/9 females; 9.9 +/- 6.9 years). Twenty of 26 patients received dual chamber systems, 6 of 26 patients single lead systems. Each patient has been followed 3 months. Pacemaker analysis at implant and 6 months later evaluated pulse width thresholds at 2.5 V (atrial 0.07 +/- 0.02 vs 0.13 +/- 0.02 ms [P = 0.01]; ventricular 0.08 +/- 0.04 ms vs 0.20 +/- 0.04 ms [P = 0.01]); sensing thresholds (atrial 4.1 +/- 0.41 mV vs 4.0 +/- 4.2 mV [P = NS]; ventricular 9.7 +/- 0.72 vs 9.3 +/- 0.94 mV [P = NS]); and impedance (atrial 345 +/- 12 vs 370 +/- 120 O [P = 0.04]; ventricular 412 +/- 17 vs 458 +/- 190 O [P < 0.01]). One volt lead failed with exit block at approximately 6 weeks. The youngest (9 months to 5 years) and smallest (6.5-18.0 kg) ten patients have each shown by venography to have at least mild venous stenosis at the lead(s) insertion site; five patients demonstrated collateral formation around asymptomatic obstruction, with no thrombus formation. The Intermedics 438-10 ThinLine pacing lead has demonstrated good and stable early postimplant electrical parameters. Angiographic evaluation in our smaller patients has shown evidence for asymptomatic venous obstruction.
authors.affiliation: Children's Heart Center at Egleston Scottish Rite, Atlanta, Georgia, USA. donofriov@Kidsheart.com
authors.forename: R M
authors.initials: RM
authors.lastname: Campbell
authors.forename: A A
authors.initials: AA
authors.lastname: Raviele
authors.forename: E J
authors.initials: EJ
authors.lastname: Hulse
authors.forename: D O
authors.initials: DO
authors.lastname: Auld
authors.forename: G J
authors.initials: GJ
authors.lastname: McRae
authors.forename: V K
authors.initials: VK
authors.lastname: Tam
authors.forename: K R
authors.initials: KR
authors.lastname: Kanter
mesh_terms: D000293:Adolescent; D000328:Adult; D001283:Atrioventricular Node / Q000601:surgery; D016121:Brachiocephalic Veins / Q000000981:diagnostic imaging; D002304:Cardiac Pacing, Artificial; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D017115:Catheter Ablation / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D004562:Electrocardiography; D004567:Electrodes, Implanted; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007223:Infant; D008133:Long QT Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008452:Maximum Allowable Concentration; D010138:Pacemaker, Artificial / Q000592:standards*; D010690:Phlebography; D019919:Prosthesis Implantation; D012189:Retrospective Studies; D012804:Sick Sinus Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D013350:Subclavian Vein / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler; D014683:Vena Cava, Superior / Q000000981:diagnostic imaging