title: Role of intraoperative electrical parameters in predicting reverse remodelling after cardiac resynchronization therapy and correlation with interventricular mechanical dyssynchrony.
abstract: OBJECTIVE
  Cardiac resynchronization therapy (CRT) was shown to reverse left ventricular (LV) remodelling in heart failure (HF) patients. We aimed to investigate whether intraoperative electrical parameters (IEP) were predictive factors of LV reverse remodelling and were correlated with mechanical dyssynchrony indexes.
  
  
  METHODS
  Eighty-six patients with HF underwent CRT. At implant, several electrical and echocardiographic parameters were evaluated and, at 6 months, responders were defined by a relative increase in LV ejection fraction ≥25% compared with baseline.
  
  
  RESULTS
  Several IEPs were shown to predict LV reverse remodelling. Receiver operating curve analysis revealed the ratio between QRS duration during biventricular pacing (BVp) and right ventricular pacing (RVp) [QRS(BVp)/QRS(RVp)] as the best predictor of LV functional recovery after CRT (AUC = 0.72; 95% confidence limit 0.57-0.82; P < 0.001). Responders showed a lower value of QRS(BVp)/QRS(RVp) when compared with non-responders (0.74 ± 0.05 vs. 0.8 ± 0.1; P < 0.005) and 0.78 was the value associated with the best predictive accuracy. The interval between the onset of RV lead and LV lead electrograms (RVegm-LVegm) during baseline rhythm correlated directly with the interventricular mechanical delay (IVMD) (r = 0.68; P < 0.0001) and with its reduction (delta IVMD) at follow-up (r = 0.66; P < 0.0005).
  
  
  CONCLUSIONS
  Intraoperative electrical parameters can predict LV functional recovery after CRT and they are correlated with interventricular mechanical resynchronization at follow-up.
authors.affiliation: Division of Cardiovascular Diseases, Azienda Ospedaliera-Universitaria Pisana, Pisa, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Zucchelli
authors.forename: Ezio
authors.initials: E
authors.lastname: Soldati
authors.forename: Andrea
authors.initials: A
authors.lastname: Di Cori
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Lucia
authors.forename: Luca
authors.initials: L
authors.lastname: Segreti
authors.forename: Gianluca
authors.initials: G
authors.lastname: Solarino
authors.forename: Gabriele
authors.initials: G
authors.lastname: Borelli
authors.forename: Vitantonio
authors.initials: V
authors.lastname: Di Bello
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Bongiorni
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058406:Cardiac Resynchronization Therapy; D004452:Echocardiography; D004562:Electrocardiography; 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*; D020257:Ventricular Remodeling