title: Interventricular delay optimization: a comparison among three different echocardiographic methods.
abstract: OBJECTIVE
  To compare three different methods for obtaining interventricular-(VV) interval optimization.
  
  
  METHODS
  A total of 30 patients undergoing cardiac resynchronization therapy (CRT) were enrolled. All the patients underwent VV-interval optimization performed with three different echocardiographic methods at seven different settings: simultaneous right (RV) and left (LV) ventricular pacing, LV stimulation only, LV preexcitation (LV+20,+40,+60 ms, respectively), RV preexcitation (RV+20 and+40 ms, respectively). Optimal VV delay was selected by: (1) measuring the aortic velocity time integral (VTI method); (2) measuring the time to maximum delay between septal and lateral longitudinal motion in the four-chamber view (velocity method); and (3) measuring the segment with maximal temporal difference of peak circumferential strain in short-axis view at papillary muscles level, (strain method). Velocity and strain methods measurements were obtained relying on two-dimensional ultrasound border tracking algorithm thus providing angle-independent measurements.
  
  
  RESULTS
  Immediately after CRT, VTI, maximum peak circumferential strain delay and maximum septal-to-lateral delay were significantly improved (P < 0.001). Particularly, VV-interval optimization determined a further improvement of these indices as compared to the other VV settings (P < 0.001). Furthermore, a substantial concordance was found between the optimal VV interval obtained according to the VTI method and velocity method (k = 0.68), between the optimal VV interval obtained according to the VTI method and strain method (k = 0.63); and between the optimal VV interval obtained according to the velocity method and strain method (k = 0.71).
  
  
  CONCLUSIONS
  VV-interval optimization was shown to determine a further benefit beyond CRT. A significant concordance was present between VV programming based on different echocardiographic methods.
authors.affiliation: Institute of Cardiology, University of Bologna and Azienda Ospedaliera S. Orsola-Maplpighi, Bologna, Italy. doc.matber@gmail.com
authors.forename: Matteo
authors.initials: M
authors.lastname: Bertini
authors.forename: Cinzia
authors.initials: C
authors.lastname: Valzania
authors.forename: Mauro
authors.initials: M
authors.lastname: Biffi
authors.forename: Cristian
authors.initials: C
authors.lastname: Martignani
authors.forename: Matteo
authors.initials: M
authors.lastname: Ziacchi
authors.forename: Stefano
authors.initials: S
authors.lastname: Pedri
authors.forename: Giulia
authors.initials: G
authors.lastname: Domenichini
authors.forename: Igor
authors.initials: I
authors.lastname: Diemberger
authors.forename: Davide
authors.initials: D
authors.lastname: Saporito
authors.forename: Guido
authors.initials: G
authors.lastname: Rocchi
authors.forename: Claudio
authors.initials: C
authors.lastname: Rapezzi
authors.forename: Angelo
authors.initials: A
authors.lastname: Branzi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000000981:diagnostic imaging* / Q000517:prevention & control*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013813:Therapy, Computer-Assisted / Q000379:methods; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000000981:diagnostic imaging* / Q000517:prevention & control*