title: Cardiac resynchronization therapy acutely improves diastolic function.
abstract: BACKGROUND
  Invasive studies have shown that cardiac resynchronization therapy (CRT) acutely improves left ventricular (LV) systolic performance and lowers filling pressures in a majority of patients with medically-refractory severe heart failure. Measurements included LV volume, ejection fraction, PWD early (E-wave) and atrial (A-wave) velocities, diastolic filling time (DFT), and DTI early diastolic mitral annular velocity (Em) at the lateral and septal annulus; PWD mitral E-wave/Em and E/FP were calculated to estimate LV filling pressures.
  
  
  RESULTS
  Immediately after CRT, LV volumes decreased and LVEF increased significantly. PWD mitral E-wave velocity decreased and E-wave duration and DFT increased significantly; mitral E/FP ratio also decreased significantly, consistent with a decrease in LV filling pressure. Patients with a pre-CRT mitral E/A ratio >1 (n = 20), demonstrated improvements in LV diastolic filling and lower filling pressures whereas those with an E/A ratio < or =1 (n = 21) did not show significant changes in diastolic indices.
  
  
  CONCLUSIONS
  The acute effects of CRT include echocardiographic evidence of reduced LV volumes and increased LVEF with improved diastolic filling and lower filling pressures; LV relaxation is not significantly altered. The benefits in diastolic function are dependent on the PWD-determined LV filling characteristics prior to CRT.
authors.affiliation: Cardiovascular Imaging and Clinical Research Core Laboratory, Cardiovascular Division, Box 8086, Washington University School of Medicine, 660 S. Euclid Ave., St Louis, MO 63310, USA. waggonea@msnotes.wustl.edu
authors.forename: Alan D
authors.initials: AD
authors.lastname: Waggoner
authors.forename: Mitchell N
authors.initials: MN
authors.lastname: Faddis
authors.forename: Marye J
authors.initials: MJ
authors.lastname: Gleva
authors.forename: Lisa
authors.initials: L
authors.lastname: de las Fuentes
authors.forename: Judy
authors.initials: J
authors.lastname: Osborn
authors.forename: Sharon
authors.initials: S
authors.lastname: Heuerman
authors.forename: Victor G
authors.initials: VG
authors.lastname: Davila-Roman
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002306:Cardiac Volume; D017147:Defibrillators, Implantable; D003971:Diastole / Q000502:physiology*; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy