title: Upgrading from single chamber right ventricular to biventricular pacing in permanently paced patients with worsening heart failure: The RD-CHF Study.
abstract: BACKGROUND
  Biventricular (BiV) stimulation lowers morbidity and mortality in patients with drug-refractory congestive heart failure (CHF), depressed left ventricular (LV) function, and ventricular dyssynchrony in absence of indication for permanent cardiac pacing. This pilot, single-blind, randomized, cross-over study examined the safety and efficacy of upgrading conventional pacing systems to BiV stimulation in patients with advanced CHF.
  
  
  METHODS
  We included 56 patients in New York Heart Association (NYHA) functional classes III or IV despite optimal drug treatment and ventricular dyssynchrony (interventriclar delay > 40 ms or LV preejection delay > 140 ms) in need of pacemaker replacement. We compared the patients' functional status, arrhythmias, and standard echocardiographic measurements during 3 months of conventional, single right ventricular (RV) versus 3 months of BiV stimulation.
  
  
  RESULTS
  There were 44 patients in the cross-over phase. QRS duration was shortened by 23% and LV preejection delay by 16% with BiV stimulation. NYHA functional class, 6-minute hall walk and quality of life score were significantly improved with BiV stimulation compared with single RV pacing by 18%, 29%, and 19%, respectively. No significant difference was observed in the ventricular arrhythmia burden or LV reverse remodeling between the 2 periods.
  
  
  CONCLUSIONS
  This pilot study showed that upgrading from RV pacing to BiV pacing significantly improves symptoms and exercise tolerance in chronically paced patients with advanced CHF and mechanical dyssynchrony.
authors.affiliation: Centre Cardio-Pneumologique, CHU, Rennes, France. christophe.leclercq@chu-rennes.fr
authors.forename: Christophe
authors.initials: C
authors.lastname: Leclercq
authors.forename: Serge
authors.initials: S
authors.lastname: Cazeau
authors.forename: David
authors.initials: D
authors.lastname: Lellouche
authors.forename: Fabien
authors.initials: F
authors.lastname: Fossati
authors.forename: Fréderic
authors.initials: F
authors.lastname: Anselme
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Davy
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sadoul
authors.forename: Didier
authors.initials: D
authors.lastname: Klug
authors.forename: Luca
authors.initials: L
authors.lastname: Mollo
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Daubert
mesh_terms: D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000517:prevention & control; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D018592:Cross-Over Studies; D018450:Disease Progression; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left