title: Improvement of congestive heart failure by upgrading of conventional to resynchronization pacemakers.
abstract: OBJECTIVE
  To compare the clinical response of patients with right ventricular apical pacing (RVAP) upgraded to cardiac resynchronization therapy (CRT) to that of previously nonpaced heart failure (HF) patients who had de novo CRT implantation.
  
  
  BACKGROUND
  The role of CRT in patients with wide QRS and HF due to RVAP is less well established than in other CRT candidates.
  
  
  METHODS
  Ninety-eight consecutive patients with CRT were studied (mean age 70, mean ejection fraction 0.23). Group A: patients having RVAP prior to CRT implantation (n = 25), group B: patients without prior RVAP (n = 73). Clinical and echocardiographic parameters were recorded prior to, and 3 months after, CRT implantation.
  
  
  RESULTS
  Group A patients had a wider QRS at baseline compared to group B (203 +/- 32 ms vs 163 +/- 30 ms respectively, P < 0.001), and a shorter 6-minute walking distance (222 +/- 118 m vs 362 +/- 119 m, respectively, P < 0.005). Otherwise, clinical and echocardiographic parameters were not different. At follow up, group A patients had an average 0.7 +/- 0.5 decrease in their NYHA functional class, compared to 0.3 +/- 0.7 in group B patients (P < 0.05). Six-minute walking distance increased by 93 +/- 113 m in group A, versus 36 +/- 120 m in group B (P = 0.22). There was no difference in echocardiographic response to CRT between the groups.
  
  
  CONCLUSIONS
  HF patients with prior RVAP demonstrate clinical improvement after upgrading to CRT that is comparable, and in some aspects, even better than that observed in HF patients with native conduction delay who undergo de novo CRT implantation.
authors.affiliation: Heart Institute, Sheba Medical Center, Tel-Hashomer, and Sackler School of Medicine, Tel-Aviv University, Israel.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Marai
authors.forename: Osnat
authors.initials: O
authors.lastname: Gurevitz
authors.forename: Shemy
authors.initials: S
authors.lastname: Carasso
authors.forename: Eyal
authors.initials: E
authors.lastname: Nof
authors.forename: David
authors.initials: D
authors.lastname: Bar-Lev
authors.forename: David
authors.initials: D
authors.lastname: Luria
authors.forename: Yaron
authors.initials: Y
authors.lastname: Arbel
authors.forename: Dov
authors.initials: D
authors.lastname: Freimark
authors.forename: Micha S
authors.initials: MS
authors.lastname: Feinberg
authors.forename: Michael
authors.initials: M
authors.lastname: Eldar
authors.forename: Michael
authors.initials: M
authors.lastname: Glikson
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006333:Heart Failure / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D016896:Treatment Outcome; D014463:Ultrasonography