title: The impact of beta-blockade on right ventricular function in mitral regurgitation.
abstract: BACKGROUND
  Although mitral regurgitation (MR) results in left ventricular (LV) volume overload, right ventricular (RV) function may also be impaired. We investigated the influence of short-term beta-blockade on RV function in patients with moderate-severe MR.
  
  
  METHODS
  Twenty-six patients were randomised in a cross-over design to receive two weeks of beta-blockade or placebo. Echocardiography was performed at baseline and at the end of the treatment periods. Measurements included: RV ejection fraction (RVEF) tricuspid annular motion and Tei index.
  
  
  RESULTS
  No differences in mean RVEF (64.0 ± 6.0 v 67.0 ± 8.0%, p=0.3), tricuspid annular motion (13.5 ± 3.0 v 14.7 ± 2.9 cm/s, p=0.5), or median Tei index (0.61 (0.54, 0.88) v 0.59 (0.54, 0.74), p=0.8) were observed between placebo and metoprolol, despite significantly longer cardiac time intervals. Tei index under both conditions was significantly reduced.
  
  
  CONCLUSIONS
  Short-term treatment with a beta-blocker did not influence RV function in these patients. Interestingly, the RV Tei index was high suggesting significant RV dysfunction despite normal RVEF.
authors.affiliation: The 2nd Hospital of Hebei Medical University, Shijiazhuang, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Hongning
authors.affiliation: Auckland City Hospital, Auckland, New Zealand.
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Stewart
authors.affiliation: Unitec, Auckland, New Zealand. Electronic address: gwhalley@unitec.ac.nz.
authors.forename: Gillian A
authors.initials: GA
authors.lastname: Whalley
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage*; D000368:Aged; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology*; D013997:Time Factors; D014463:Ultrasonography; D016278:Ventricular Function, Right / Q000187:drug effects*
chemical_list: D000319:Adrenergic beta-Antagonists
keywords: Beta-blockers; Doppler; Echocardiography; Mitral regurgitation; Tei index