title: Over-time mitral regurgitation changes following cardiac resynchronization therapy.
abstract: OBJECTIVE
  Mitral regurgitation (MR) is a leading cause of mortality in patients with heart failure (HF). Cardiac resynchronization therapy (CRT) has been shown to improve MR in these patients, but maintenance of MR improvement after CRT implantation has not yet been evaluated. We aimed to evaluate the post-CRT improvement pattern of MR in a 6-month follow-up period.
  
  
  METHODS
  65 consecutive patients scheduled for CRT implantation with inclusion criteria of moderate to severe heart failure, left ventricular ejection fraction (LVEF) <or=35%, and QRS duration >120 ms with left bundle branch block configuration were invited to participate. 60 patients with MR were registered. Clinical, electrocardiographic and echocardiographic evaluations were recorded before CRT implantation and 3 and 6 months after.
  
  
  RESULTS
  We found significant improvement in MR score, NYHA class, QRS duration, LVEF and left ventricular end diastolic diameter (LVEDD) at the 3-month follow-up (p<0.001). These parameters also improved significantly (p<0.0001) between the 3 and 6-month follow-ups except for the MR score, which did not show any significant improvement.
  
  
  CONCLUSIONS
  MR improvement was sustained after CRT implantation between the 3 and 6-month follow-ups.
authors.affiliation: Electrophysiology and Pacemaker, Clinical Research Unit, Baqiyatallah University of Medical Sciences, Tehran, Iran. parsi.bakhshian@gmail.com
authors.forename: R B
authors.initials: RB
authors.lastname: Kelarijani
authors.forename: Y
authors.initials: Y
authors.lastname: Dadjoo
authors.forename: H
authors.initials: H
authors.lastname: Chalian
authors.forename: M
authors.initials: M
authors.lastname: Naserbakht
authors.forename: K
authors.initials: K
authors.lastname: Kabir
authors.forename: D K
authors.initials: DK
authors.lastname: Saleh
mesh_terms: D002304:Cardiac Pacing, Artificial; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*; D013318:Stroke Volume; D014463:Ultrasonography