title: [Non-invasive evaluation of left ventricular function (systolic time interval) in patients using double-chamber pacemakers programmed on DDD and VVI].
abstract: OBJECTIVE
  To evaluate changes on left ventricular function as assessed by systolic time intervals (STI), by programming "physiological" pacemakers either on VVI or DDD mode.
  
  
  METHODS
  Comparison of STI values--electromechanical systole (QS2); left ventricular ejection time (LVET); pre-ejection period (PEP); PEP/LVET--in patients submitted to double chamber pacing programmed in DDD or VVI mode.
  
  
  METHODS
  Cardiac Pacing Center in a Department of Cardiology at a University Hospital.
  
  
  METHODS
  We have studied 12 patients (3 men, 9 women), mean age 56.16 years (range 25-76 years) treated with double chamber pacing.
  
  
  METHODS
  Initial measurements of STI in DDD or one week in VVI mode, and again after one week in DDD mode.
  
  
  RESULTS
  Significant changes were found after the first week in VVI pacing, versus baseline determination in DDD pacing, for LVET, PEP, and PEP/LVET (p less than 0.05). At the end of the second week (DDD pacing), there were also statistically significant differences for QS2 (P less than 0.05), LVET (P less than 0.01) and PEP/LVET (P less than 0.05) values when compared with the ones obtained in VVI pacing, at the end of the preceding week. No significant changes were found between the initial and the final STI determinations (both in DDD pacing).
  
  
  CONCLUSIONS
  We concluded for a better performance of the left ventricle at rest when "physiological" pacing is compared with VVI pacing.
authors.forename: F
authors.initials: F
authors.lastname: Paisana
authors.forename: L A
authors.initials: LA
authors.lastname: Providência
authors.forename: J
authors.initials: J
authors.lastname: Cristóvão
authors.forename: H
authors.initials: H
authors.lastname: Faria
authors.forename: M
authors.initials: M
authors.lastname: Pêgo
authors.forename: J
authors.initials: J
authors.lastname: Calisto
authors.forename: J
authors.initials: J
authors.lastname: Morais
authors.forename: C
authors.initials: C
authors.lastname: Andrade
authors.forename: V
authors.initials: V
authors.lastname: Monteiro
authors.forename: M L
authors.initials: ML
authors.lastname: Gouveia
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006327:Heart Block / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D010138:Pacemaker, Artificial; D013318:Stroke Volume / Q000502:physiology*; D013599:Systole / Q000502:physiology*
vernacular_title: Avaliação não invasiva da função ventricular esquerda (tempos sistólicos) em doentes portadores de pacemakers de dupla câmara programados em DDD e VVI.