title: Upgrading of VVIR pacemakers with nonfunctional endocardial ventricular leads to VDD pacemakers in adolescents.
abstract: BACKGROUND
  In some children with ventricular rate responsive demand (VVIR) pacemakers (PM), transvenous leads fail for technical reasons or patient's growth.
  
  
  OBJECTIVE
  The aim of this study is to describe our experience in adolescents with a nonfunctional ventricular lead in whom the lead was abandoned and an additional VDD lead was implanted. Of the 136 children who received a VVIR PM with an endocardial lead in our center, seven patients aged 7 (0.3-12) years [median (range)] at initial implantation, after 10 (5-15) years showed lead malfunction and underwent atrial synchronous ventricular inhibited pacing (VDD) PM upgrading at 16 (10-20) years.
  
  
  RESULTS
  The VDD lead was inserted through the ipsilateral subclavian vein in five patients, the contralateral in two (venous occlusion in one and for operator choice in the first patient). The tip was positioned into the right ventricular apex, the atrial dipole along the lateral atrial wall. Fluoroscopy times were not significantly different from those measured in SSI PM implantation and in VVIR dual-chamber demand pacing (VVIR-DDD) upgrading. There were no intraprocedural complications. Follow-up duration is 12 (6-62) months. The VDD PM showed good function, no undersensing or oversensing. Tricuspid damage, new venous occlusion, and "twisting" of the two leads at x-ray were not documented. The first patient showed an infection of the old PM pocket after 1 year, local pain after 3 years, and endocarditis of the leads after 5 years.
  
  
  CONCLUSIONS
  The upgrading of VVIR PM to VDD PM with the abandonment of the nonfunctional lead is feasible, with no intraprocedural complications and good PM function. Lead endocarditis occurred in one patient.
authors.affiliation: Department of Pediatric Cardiology, Bambino Gesù Pediatric Hospital, Rome, Italy. silvetti@opbg.net
authors.forename: Massimo S
authors.initials: MS
authors.lastname: Silvetti
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Drago
mesh_terms: D000293:Adolescent; D001283:Atrioventricular Node / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002648:Child; D015150:Echocardiography, Doppler; D005260:Female; D006327:Heart Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011474:Prosthesis Design; D011475:Prosthesis Failure; D018709:Statistics, Nonparametric; D016896:Treatment Outcome