title: Role of severe functional mitral regurgitation in predicting electrical remodeling in idiopathic dilated cardiomyopathy.
abstract: OBJECTIVE
  To investigate incidence and predictors of clinically relevant QRS widening (predefined as > or = 10% with respect to baseline) in idiopathic dilated cardiomyopathy (IDC) and particularly the prognostic role of functional mitral regurgitation (MR). Although QRS widening in left ventricular systolic dysfunction carries relevant prognostic and therapeutic implications, its incidence and predictors in patients with IDC remain unknown.
  
  
  METHODS
  We analyzed 114 patients with IDC receiving optimized medical treatment (age 52 +/- 10 years; 44% males; 36% New York Heart Association class III-IV) who underwent clinical, echocardiographic, hemodynamic, and laboratory evaluations and at least two electrocardiograms > or = 6 months after the index evaluation.
  
  
  RESULTS
  During follow-up (median 20 months), 19 (17%) patients developed clinically relevant QRS widening, corresponding to an incidence of 8% per year. At multivariable analysis, the presence of echocardiographically detected severe MR (P = 0.029) and mean right atrial pressure (RAP) by right heart catheterization (P = 0.021) independently predicted clinically relevant QRS widening.
  
  
  CONCLUSIONS
  Clinically relevant QRS widening is relatively frequent in IDC despite optimized medical treatment, and is independently predicted by MR severity and high RAP. IDC patients presenting either of these risk-factors might benefit from strict follow-up, which could also allow timely detection of the onset of indications for cardiac resynchronization therapy.
authors.affiliation: Institute of Cardiology, Policlinico Hospital of Modena and Reggio Emilia, Italy. olmoberg@libero.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Barbieri
authors.forename: Francesco
authors.initials: F
authors.lastname: Grigioni
authors.forename: Francesca
authors.initials: F
authors.lastname: Bursi
authors.forename: Letizia
authors.initials: L
authors.lastname: Reggianini
authors.forename: Silvia
authors.initials: S
authors.lastname: Bonatti
authors.forename: Caterina
authors.initials: C
authors.lastname: Ricci
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Boriani
authors.forename: Antonio
authors.initials: A
authors.lastname: Russo
authors.forename: Carlo
authors.initials: C
authors.lastname: Magelli
authors.forename: Angelo
authors.initials: A
authors.lastname: Branzi
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Modena
mesh_terms: D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000503:physiopathology*; D015999:Multivariate Analysis; D009200:Myocardial Contraction / Q000502:physiology; D011379:Prognosis; D018570:Risk Assessment