title: [Safety and effectiveness of single-lead VDD pacing].
abstract: OBJECTIVE
  Single-lead VDD pacing provides the physiological benefits of atrioventricular synchrony with the convenience of a single-lead system. However, concern remains about the method's safety and effectiveness.
  
  
  METHODS
  In total, 700 patients with single-lead VDD pacemakers were evaluated retrospectively. The following parameters were recorded: age, sex, etiology, the symptoms and electrocardiographic diagnosis that justified pacemaker implantation, the venous access route used for implantation, atrial sensing at implantation, atrial undersensing at follow-up, the occurrence of supraventricular tachyarrhythmias, and final pacing mode.
  
  
  RESULTS
  Third-degree atrioventricular block was the main indication for pacemaker implantation (66.4%). The most commonly used venous access route was via the right cephalic vein (49.1%). At implantation, the mean atrial signal was 1.8 (4 1.15) mV. During follow-up, significant atrial undersensing occurred in 7.7% of patients; in 1.9%, it could not be corrected by device reprogramming. Uncontrollable supraventricular arrhythmias were observed in 6.4% of patients. Symptomatic sinus node disease was rare. By the end of follow-up, 91.4% of patients were still on VDD pacing, while, in 8.3%, the pacemaker had to be reprogrammed to the VVI mode. Only 0.3% required atrial lead implantation for DDD pacing. Left-side venous access during implantation was a independent predictora of atrial undersensing at follow-up. Low values of atrial detection at implant did not reach statistical signification although it showed a remarkable trend.
  
  
  CONCLUSIONS
  Single-lead VDD pacing seems to be safe and effective when appropriately indicated. Our findings are consistent with those of previously published studies.
authors.affiliation: Unidad de Marcapasos, Servicio de Cardiología. Hospital Universitario Miguel Servet, Zaragoza, España. maruancarlos@yahoo.com
authors.forename: Maruan C
authors.initials: MC
authors.lastname: Chabbar Boudet
authors.forename: Antonella
authors.initials: A
authors.lastname: Lukic
authors.forename: José G
authors.initials: JG
authors.lastname: Galache Osuna
authors.forename: Jesús
authors.initials: J
authors.lastname: De Juan Montiel
authors.forename: Eduardo
authors.initials: E
authors.lastname: Cay Diarte
authors.forename: José A
authors.initials: JA
authors.lastname: Diarte de Miguel
authors.forename: Luis J
authors.initials: LJ
authors.lastname: Placer Peralta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D004567:Electrodes, Implanted / Q000009:adverse effects; D005260:Female; D006327:Heart Block / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D012449:Safety; D016896:Treatment Outcome