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.

Age, Size, and Lead Factors Alone Do Not Predict Venous Obstruction in Children and Young Adults with Transvenous Lead Systems

“…In the Figa study, screening for obstruction was performed with ultrasound, and angiography was only used in a small subgroup of patients to confirm and grade the obstruction. As evidenced by the large number of false negatives seen with ultrasound in the earlier pediatric study, 10 ultrasound is less sensitive for the diagnosis of venous occlusion and may give a false representation of the incidence of obstruction. Figa's study screened outpatients in a pediatric pacemaker clinic while our study evaluated consecutive patients undergoing repeat pacemaker procedures.…”

Endocardial Atrial Pacing Lead Implantation and Midterm Follow‐Up in Young Patients with Sinus Node Dysfunction After the Fontan Procedure

“…In some very young patients who have had the Fontan procedure, epicardial atrial or transmural lead placement may be the best options because of small vessel size and need for growth accommodation 9,17 . However, current technology allows for implantation of pacing leads with body diameter as small as 1.7 mm that may be suitable for small vessels 23 . The surgical creation of the Fontan baffle precludes access to the ventricle for pacing in most cases.…”

Upgrade of Single Chamber Pacemakers with Transvenous Leads to Dual Chamber Pacemakers in Pediatric and Young Adult Patients

“…Furthermore, clinically unsuspected venous occlusion 3,4 may complicate new procedures requiring lead extraction or vessel angioplasty 15,16 . There is also concern regarding the long‐term outcome of leads that may be extracted and replaced, 15 or abandoned and substituted 17 because of somatic growth or intrinsic or extrinsic deterioration 18 .…”

“…The endocardial pacing mode of choice in children with complete atrioventricular block (AVB) and normal ventricular function is ventricular rate responsive demand pacing (VVIR) 1,2 . VVIR pacing is sufficient for maintaining good cardiac function in most children, and the transvenous implantation of a single lead reduces the surgical risk, the operative time, and the late risk of venous thrombosis 2–4 . When the child becomes an adolescent or young adult, VVIR pacing may not be adequate, and an upgrade to a dual chamber (DDD) or to a VDD pacing system might be considered.…”