title: A prospective randomized evaluation of VV delay optimization in CRT-D recipients: echocardiographic observations from the RHYTHM II ICD study.
abstract: BACKGROUND
  All current cardiac resynchronization therapy (CRT) devices allow the programming of the atrioventricular (AV/PV) delays and the sequential stimulation of the ventricles via the inter ventricular (VV) delay.
  
  
  OBJECTIVE
  This post hoc analysis of the RHYTHM II study was conducted to compare the reverse remodeling associated with VV delay optimization in patients randomly assigned to simultaneous (SIM) biventricular stimulation versus patients assigned to optimized VV delay programming (OPT) (1:3 randomization scheme).
  
  
  METHODS
  The analysis included 14 patients assigned to the SIM group and 34 patients to the OPT group who completed the 6-month follow-up period with paired echocardiographic recordings.
  
  
  RESULTS
  In both study groups, changes consistent with left ventricular (LV) remodeling were observed between baseline and 6 months, with significant improvements in LV function and decrease in LV dimensions. In the OPT group, there was also a decrease in left atrial diameter and mitral valve closure to opening time. At 6 months, the overall proportion of echocardiographic responders (> or =10% decrease in LV end-systolic volume or > or =5% absolute increase in LV ejection fraction) was similar in both groups. The optimal AV/VV delays, evaluated by maximization of LV outflow tract velocity time integral, changed over time.
  
  
  CONCLUSIONS
  Ventriculo-ventricular delay optimization was associated with better immediate hemodynamic function than simultaneous biventricular stimulation, though did not promote additional reverse remodeling at 6 months and did not increase the proportion of echocardiographic responders to CRT. Optimization of both the AV and VV intervals was patient-specific and optimal values changed over time.
authors.affiliation: Institute of Cardiology, University of Bologna, Azienda Ospedaliera S.Orsola-Malpighi, Bologna, Italy. giuseppe.boriani@unibo.it
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Cord Paul
authors.initials: CP
authors.lastname: Müller
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Seidl
authors.forename: Rainer
authors.initials: R
authors.lastname: Grove
authors.forename: Jürgen
authors.initials: J
authors.lastname: Vogt
authors.forename: Wilfried
authors.initials: W
authors.lastname: Danschel
authors.forename: Andreas
authors.initials: A
authors.lastname: Schuchert
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Deharo
authors.forename: Thorsten
authors.initials: T
authors.lastname: Becker
authors.forename: Eric
authors.initials: E
authors.lastname: Boulogne
authors.forename: Hans Joachim
authors.initials: HJ
authors.lastname: Trappe
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004452:Echocardiography; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000517:prevention & control*