title: VDD pacemaker replacement independently of the implanted lead: a prospective study.
abstract: BACKGROUND
  Single-lead VDD pacing is effective, safe and reliable. The only still open, practical issue is represented by the theoretical need of replacing each device with a similar one compatible with the already implanted lead to guarantee the performance of the system. The aim of our study was to investigate the atrial sensing performance of VDD pacemakers working in combination with non-dedicated chronic leads.
  
  
  METHODS
  We enrolled 16 consecutive patients (12 males, 4 females, mean age 78 +/- 7 years) admitted to our institution for end of life of the battery. Atrial dipoles ranged from 5 to 30 mm. All replacements were done with a VDD(R) Saphir 3 (Vitatron) designed for an atrial dipole of 8.6 mm.
  
  
  RESULTS
  All pacemakers were found to be performing well without any complaint by the patients imputable to stimulation defects. The P-wave amplitudes measured by the old and new pacemakers are similar and respectively 0.64 +/- 0.40 vs 0.73 +/- 0.53 mV (p = NS). So the old and new devices detect similar P waves. The atrial sensing percentage at 1 month of follow-up with the new pacemaker was even better than that of the old one (97 +/- 4 vs 95 +/- 3% respectively, p = 0.016): this is not imputable to the pacemaker but to the higher programmed atrial sensitivity (0.17 +/- 0.06 vs 0.18 +/- 0.07 mV respectively, p = NS).
  
  
  CONCLUSIONS
  Independently of the implanted lead, the replacement of VDD pacemakers with devices designed for a short dipole is feasible, safe and reliable. This possibility overcomes a presumed limitation of this pacing modality.
authors.affiliation: Division of Cardiology, Area Aretina Nord Hospital, Arezzo.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fabiani
authors.forename: Antonio
authors.initials: A
authors.lastname: Burali
authors.forename: Enrico
authors.initials: E
authors.lastname: Manfredini
authors.forename: Giorgio
authors.initials: G
authors.lastname: Corbucci
authors.forename: Leonardo
authors.initials: L
authors.lastname: Bolognese
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015716:Electrocardiography, Ambulatory; D004567:Electrodes, Implanted; D004867:Equipment Design; D004868:Equipment Failure; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000175:diagnosis / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013686:Telemetry