Pronounced improvement in systolic and diastolic ventricular long axis function after treatment with metoprolol

Background: Although it is well known that left ventricular (LV) function improves after treatment with beta-blockers in heart failure, little attention has been paid to the effects on LV long axis (LAX) function. Aims: To evaluate LV LAX function after treatment with metoprolol, and to assess whether LV LAX contractile reserve could predict future long-term improvement. Methods: Twenty-four heart failure patients were randomised to metoprolol or placebo for 6 months, followed by 6 months of open treatment with metoprolol. Rest and dobutamine stress echocardiography (DSE) was performed before and after each treatment period. Results: After treatment with metoprolol, LV LAX function improved significantly, systolic velocity from 29 +/- 8 to 32 +/- 15 mm/s, p < 0.01 (metoprolol) vs. 28 +/- 7 to 28 +/- 11 mm/s, ns (placebo); atrioventricular plane fractional shortening (AVP-FS) from 5.4 +/- 2.1 to 7.4 +/- 2.7%, p < 0.001 (metoprolol) vs. 5.9 +/- 2.1 to 5.8 +/- 2.9%, ns (placebo). The improvement in function was maintained during DSE. LV LAX contractile reserve could not predict treatment response; the treatment effect on LV LAX function was significantly greater than the contractile reserve at baseline. The relative improvement in LV LAX function after metoprolol was 38%, compared with a 20% improvement in LV ejection fraction (EF). Conclusion: A significant improvement in LV LAX function was observed after treatment with metoprolol. AVP-FS and systolic velocities increased significantly, and to a greater extent than LVER (C) 2007 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.