The impact of beta-blockade on right ventricular function in mitral regurgitation.

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.