title: Atrioventricular delay optimization by doppler-derived left ventricular dP/dt improves 6-month outcome of resynchronized patients.
abstract: BACKGROUND
  Atrioventricular (AV) interval optimization, ensuring the best filling and the abolishment of presystolic mitral regurgitation, is crucial for the efficacy of cardiac resynchronization therapy (CRT). The methods proposed to optimize AV delay have many limitations. The maximum left ventricular pressure derivative (LV dP/dt)--an index of cardiac performance--could provide a clue for AV optimization. DP/dt can be calculated by the Doppler curve of mitral regurgitation jet and it is related to micromanometer-derived dP/dt.
  
  
  OBJECTIVE
  The aim of this study was to assess whether optimal AV delay, defined as the highest noninvasive dP/dt, may provide clinical and functional benefits in CRT patients.
  
  
  METHODS
  Of 41 consecutive patients, 23 echo Doppler recordings were obtained at AV delays of 60, 80, 100, 120, 140, 160, 180 ms (Group I). Three patients were discarded because of suboptimal Doppler signal. In 15 patients an empiric AV delay of 120 ms was chosen (Group II). Both groups were programmed to atriosynchronous pacing mode and synchronous VV stimulation.
  
  
  RESULTS
  In Group I optimal AV delay was 60 ms in one patient, 80 ms in 6, 100 in 6, 120 in 8, 140 in 2. At 6 months follow-up, Group I showed a significantly lower NYHA class (2.1 +/- 0.1 vs 3 +/- 0.2 P < 0.01) and higher LV ejection fraction (LVEF): 32.1 + 1 versus 27.5 +/- 1.6% (P < 0.05) as compared to Group II.
  
  
  CONCLUSIONS
  Doppler-derived dP/dt for AV delay optimization determines better functional class and LVEF at 6 months follow-up relative to an empiric AV delay program.
authors.affiliation: CNR Clinical Physiology Institute, Pisa, Italy. morales@ifc.cnr.it
authors.forename: Maria-Aurora
authors.initials: MA
authors.lastname: Morales
authors.forename: Umberto
authors.initials: U
authors.lastname: Startari
authors.forename: Luca
authors.initials: L
authors.lastname: Panchetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Rossi
authors.forename: Marcello
authors.initials: M
authors.lastname: Piacenti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001283:Atrioventricular Node / Q000502:physiology*; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D011312:Pressure; D013997:Time Factors; D016277:Ventricular Function, Left