title: Optimization of cardiac resynchronization guided by Doppler echocardiography: haemodynamic improvement and intraindividual variability with different pacing configurations and atrioventricular delays.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) improves symptoms in heart failure patients with intraventricular conduction delay (IVCD). Different pacing modalities produce variable activation patterns and are likely to result in different haemodynamic changes. The objective of this study was to demonstrate acute haemodynamic changes with different CRT configurations.
  
  
  RESULTS
  In 26 patients (left ventricular ejection fraction 22.7+/-6.1%, QRS 176+/-29 ms, New York Heart Association III/IV 18/8), a CRT device was implanted. An optimization procedure was performed including left (LVPEI) and right ventricular pre-ejection intervals, interventricular mechanical delay (IVD), left ventricular filling fraction (FTc), and myocardial performance index (MPI) during left and biventricular pacing with three different atrioventricular (AV) delays. An optimal mode and AV delay were defined. LVPEI changed from 166+/-27 to 139+/-25 ms, IVD from 49+/-19 to 6+/-18 ms, MPI from 0.98+/-0.25 to 0.62+/-0.22, and FTc from 0.42+/-0.08 to 0.51+/-0.08 (P<0.001 for all comparisons). The variability was 39+/-20 ms for LVPEI, 55+/-24 ms for IVD, 0.11+/-0.07 for FTc, and 0.35+/-0.18 for MPI.
  
  
  CONCLUSIONS
  Optimized resynchronization in heart failure patients with IVCD produces marked acute improvement of the altered cardiac cycle timing. The variability of Doppler parameters with different CRT modalities underlines the necessity of individualized settings and suggests that the patients' benefit may be jeopardized without optimization.
authors.affiliation: Department of Cardiology, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353 Berlin, Germany. martin.stockburger@charite.de
authors.forename: Martin
authors.initials: M
authors.lastname: Stockburger
authors.forename: Suzanne
authors.initials: S
authors.lastname: Fateh-Moghadam
authors.forename: Aischa
authors.initials: A
authors.lastname: Nitardy
authors.forename: Holger
authors.initials: H
authors.lastname: Langreck
authors.forename: Wilhelm
authors.initials: W
authors.lastname: Haverkamp
authors.forename: Rainer
authors.initials: R
authors.lastname: Dietz
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology