title: Cardiac resynchronization therapy: variations in echo-guided optimized atrioventricular and interventricular delays during follow-up.
abstract: BACKGROUND
  Relatively few data are available on long-term echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay programming in cardiac resynchronization therapy (CRT). We assessed variations in optimized AV and VV delays during long-term follow-up.
  
  
  METHODS
  Thirty-seven consecutive heart failure patients received Doppler echocardiographic optimization of AV and VV delay within 48 hours from CRT device implantation, at 6 months and at 12 months (the last for the first enrolled 14 patients).
  
  
  RESULTS
  After implantation, median optimized AV delay was 100 ms (range, 45 ms); VV optimization led to simultaneous biventricular activation in 4 patients, left ventricular preactivation in 17 patients and right ventricular preactivation in 16 patients. At 12 months median AV delay decreased to 85 ms (23 ms) (P < 0.05 vs. baseline). With respect to previous assessment, VV delay variations > or =40 ms were observed in 41% of the patients at 6 months and in 57% of the tested patients at 12 months. A nonconcordance (by Kappa test) of optimized VV delays was found between each new assessment and the previous one. VV delay optimization was associated with significant (P < 0.001) increases in aortic velocity time integral both at baseline and during follow-up.
  
  
  CONCLUSIONS
  Echocardiographic optimization of AV and VV delay is associated with broad intraindividual variability during follow-up. A new assessment of optimized VV delays during long-term follow-up reveals a nonconcordance with previous values and provides increases in forward stroke volume.
authors: Institute of Cardiology, University of Bologna and Azienda Ospedaliera S.Orsola-Malpighi, Via Massarenti 9, 40138 Bologna, Italy. cinzia.valzania2@studio.unibo.it
authors: Cinzia
authors: C
authors: Valzania
authors: Mauro
authors: M
authors: Biffi
authors: Cristian
authors: C
authors: Martignani
authors: Igor
authors: I
authors: Diemberger
authors: Matteo
authors: M
authors: Bertini
authors: Matteo
authors: M
authors: Ziacchi
authors: Letizia
authors: L
authors: Bacchi
authors: Guido
authors: G
authors: Rocchi
authors: Claudio
authors: C
authors: Rapezzi
authors: Angelo
authors: A
authors: Branzi
authors: Giuseppe
authors: G
authors: Boriani
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome