title: Value of VDD-pacing systems in patients with atrioventricular block: experience over a decade.
abstract: BACKGROUND
  Even though current guidelines suggest the use of VDD pacemakers in patients with AV block and normal sinus node function, a DDD system is often preferred for fear of either long-term atrial undersensing or late sinus node dysfunction and the resultant need for system upgrades.
  
  
  METHODS
  We evaluated the long-term follow-up of all VDD pacemakers implanted in our center between 1992 and 2001 regarding atrial sensing, maintenance of AV synchrony, incidence of atrial fibrillation (AF), or the need for system upgrade, respectively.
  
  
  RESULTS
  320 consecutive patients (56% men, age 75+/-13 years) received a VDD pacemaker for the following indications: third-degree AV block 54%, second-degree AV block 34%, fascicular block with first-degree AV block and syncope 6%, others 6%. 138 patients (43%) died during follow-up, 3.8+/-2.3 years after implantation. Follow-up duration was 6.1+/-2.5 years in the remaining patients. At the last follow-up, 268 pacemakers (84%) were programmed to the VDD mode, 47 pacemakers (15%) were permanently programmed to the VVI mode (AF 36, undersensing 7, others 4, respectively). In five patients a DDD upgrade was necessary for sinus node dysfunction (3) or lead defect (2). Lead revision was performed in 19 patients (6%) (ventricular lead dislocation 7, atrial undersensing 6, lead fracture 3, others 2, respectively).
  
  
  CONCLUSIONS
  VDD pacemakers have an excellent long-term performance in patients with AV block. They have a very low incidence of lead revisions for atrial undersensing (2%) and DDD upgrades for secondary sinus node dysfunction (1%).
authors.affiliation: Department of Cardiology, University Hospital Basel, Petersgraben 4, CH-4031 Basel, Switzerland. bschaer@uhbs.ch
authors.forename: Beat Andreas
authors.initials: BA
authors.lastname: Schaer
authors.forename: Markus
authors.initials: M
authors.lastname: Weinbacher
authors.forename: Michael Johannes
authors.initials: MJ
authors.lastname: Zellweger
authors.forename: Christian
authors.initials: C
authors.lastname: Sticherling
authors.forename: Stefan
authors.initials: S
authors.lastname: Osswald
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial / Q000639:trends*; D012189:Retrospective Studies; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000503:physiopathology / Q000628:therapy*