title: Biventricular pacing improves clinical behavior and reduces prevalence of ventricular arrhythmia in patients with heart failure.
abstract: OBJECTIVE
  To analyze the influence of biventricular pacing (BP) on clinical behavior, ventricular arrhythmia (VA) prevalence, and left ventricular ejection fraction (LV EF) by gated ventriculography.
  
  
  METHODS
  Twenty-four patients with left bundle branch block (LBBB) and NYHA class III and IV underwent pacemaker implantation and were randomized either to the conventional or BP group, all receiving BP after 6 months.
  
  
  RESULTS
  Sixteen patients were in NYHA class IV (66.6%) and 8 were in class III (33.4%). After 1-year follow-up, 14 patients were in class II (70%) and 5 were in class III (25%). Two sudden cardiac deaths occurred. A significant reduction in QRS length was found with BP (p=0.006). A significant statistical increase, from a mean of 19.13 +/- 5.19% (at baseline) to 25.33 +/- 5.90% (with BP) was observed in LVEF Premature ventricular contraction prevalence decreased from a mean of 10,670.00 +/- 12,595.39 SD or to a mean of 3,007.00 +/- 3,216.63 SD PVC/24 h with BP (p<0.05). Regarding the hospital admission rate over 1 year, we observed a significant reduction from 60. To 16 admissions with BP (p<0.05).
  
  
  CONCLUSIONS
  Patients with LBBB and severe heart failure experienced, with BP, a significant NYHA class and LVEF improvement. A reduction in the hospital admission rate and VA prevalence also occurred.
authors.affiliation: Heart Institute, Medical School, University of São Paulo, São Paulo, SP, Brazil. martino@incor.usp.br
authors.forename: Martino
authors.initials: M
authors.lastname: Martinelli Filho
authors.forename: Anísio A A
authors.initials: AA
authors.lastname: Pedrosa
authors.forename: Roberto
authors.initials: R
authors.lastname: Costa
authors.forename: Silvana A D
authors.initials: SA
authors.lastname: Nishioka
authors.forename: Sérgio F
authors.initials: SF
authors.lastname: Siqueira
authors.forename: Wagner T
authors.initials: WT
authors.lastname: Tamaki
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sosa
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy*; D002303:Cardiac Output, Low / Q000150:complications / Q000503:physiopathology* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D013318:Stroke Volume