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 LVEF.