title: Temporal variation in optimal atrioventricular and interventricular delay during cardiac resynchronization therapy.
abstract: BACKGROUND
  Tailored atrioventricular delay (AVd) and interventricular delay (VVd) combination improves hemodynamics in patients treated with cardiac resynchronization therapy (CRT). Whether tailored AVd-VVd combination changes over time is not known.
  
  
  RESULTS
  Twenty-two patients (18 M, aged 69.9 +/- 12.5 years, New York Heart Association class III, QRS > or = 130 ms, ejection fraction 29.6 +/- 8.8%) were implanted with a biventricular device with programmable VVd. Myocardial performance index (MPI) was evaluated during pacing at different VVds and AVds at baseline and after 6 and 12 months. The optimal AVd-VVd combination was identified by the minimum MPI. After optimization, the appropriate AVd-VVd combination was programmed in each patient. MPI at 6-month follow-up after optimization was significantly higher compared with baseline (.79 +/- .21 vs. .59 +/- .15, P < .05). Re-optimization of AVd-VVd combination was required after 6 months in 21 of 22 (95%) patients. Re-optimization significantly reduced MPI compared with the value prior to re-optimization (.56 +/- .15 vs. .79 +/- .21, P < .05). The MPI remained unchanged at 12-month compared with 6-month follow-up (.59 +/- .19 vs. .56 +/-.15, P = NS). Clinical symptoms and reverse left ventricular remodeling were sustained at 6-month and 12-month follow-up.
  
  
  CONCLUSIONS
  Optimal AVd and VVd combination changes over time in patients with heart failure. Sustained improvement in clinical symptoms and reverse left ventricular remodeling after CRT are not temporally associated with improvement in MPI.
authors.affiliation: Division of Cardiology, Clinica Medica Careggi, Florence, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Porciani
authors.forename: Cristina
authors.initials: C
authors.lastname: Dondina
authors.forename: Roberto
authors.initials: R
authors.lastname: Macioce
authors.forename: Gabriele
authors.initials: G
authors.lastname: Demarchi
authors.forename: Francesco
authors.initials: F
authors.lastname: Cappelli
authors.forename: Alessio
authors.initials: A
authors.lastname: Lilli
authors.forename: Alessia
authors.initials: A
authors.lastname: Pappone
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ricciardi
authors.forename: Paolo C
authors.initials: PC
authors.lastname: Colombo
authors.forename: Margherita
authors.initials: M
authors.lastname: Padeletti
authors.forename: Sanja
authors.initials: S
authors.lastname: Jelic
authors.forename: Luigi
authors.initials: L
authors.lastname: Padeletti
mesh_terms: D000368:Aged; D002303:Cardiac Output, Low / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000503:physiopathology*; D006325:Heart Atria; D006352:Heart Ventricles; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome