title: DDD versus VVIR versus VVI mode in patients with indication to dual-chamber stimulation: a prospective, randomized, controlled, single-blind study.
abstract: BACKGROUND
  The aim of this study was to compare VVI, VVIR and DDD modes in patients with indication to dual-chamber stimulation, depending on left ventricular function.
  
  
  METHODS
  Two groups of patients were implanted with a DDD pacemaker: Group I with ejection fraction > 40% and Group II with ejection fraction < 40%. Patients with a history of atrial arrhythmia or retrograde conduction were excluded. At follow-up (1 month each) quality of life (QoL), patient preference and echo parameters were collected. At hospital discharge all patients were programmed in DDD for 1 month and then randomized to VVI or VVIR mode. At the end of the period in VVI or VVIR mode each patient underwent a control period in DDD and then was programmed in VVIR or VVI mode.
  
  
  RESULTS
  Seventeen patients out of 23 preferred DDD mode and 6 did not perceive any subjective difference among DDD, VVI and VVIR modes (4/9 in Group I and 2/14 in Group II, p = 0.0017). QoL was significantly different between the two groups and at each follow-up showed the best values in DDD. The correlation between QoL and Tei index was 0.62 in Group I (p < 0.001) and 0.35 in Group II (p = 0.001). Neither ejection fraction nor fractional shortening showed any significant difference during the three phases of the study.
  
  
  CONCLUSIONS
  Most patients preferred the DDD mode. The Tei index showed a good correlation with QoL and both QoL and Tei index significantly improved with DDD mode as compared to VVI and VVIR.
authors.affiliation: Department of Cardiology, General Hospital, Conegliano (TV), Italy.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Moro
authors.forename: Francesco
authors.initials: F
authors.lastname: Caprioglio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Berton
authors.forename: Carlo
authors.initials: C
authors.lastname: Marcon
authors.forename: Umberto
authors.initials: U
authors.lastname: Riva
authors.forename: Giorgio
authors.initials: G
authors.lastname: Corbucci
authors.forename: Pietro
authors.initials: P
authors.lastname: Delise
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000503:physiopathology / Q000628:therapy; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D011788:Quality of Life; D012804:Sick Sinus Syndrome / Q000503:physiopathology / Q000628:therapy; D016037:Single-Blind Method; D013318:Stroke Volume; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy