The authors evaluated the effects of beta blockers (
metoprolol) and
calcium channel blockers (
diltiazem) in patients having mild to moderate
mitral stenosis (MS) with sinus rhythm. Eighty patients with a complaint of
dyspnea with diagnosed MS were included in this study. Patients were randomized into
metoprolol and
diltiazem groups. The first group received oral
diltiazem treatment for 3 months following an i.v. dose of 25 mg
diltiazem. The second group received oral
metoprolol for 3 months following an i.v. dose of 5 mg
metoprolol. All patients performed a treadmill exercise test at the beginning of and after 3 months of treatment. Transthoracic echocardiographic studies were also performed following the i.v.
drug administration and after 3 months of treatment. In addition,
oxygen uptakes of patients were measured before and after the stress and after 3 months of treatment. Decreases in peak gradient (PG) and mean transmitral gradient (MG) were observed in the
metoprolol group after i.v. and oral
metoprolol treatment. A prolongation of exercise time in treadmill exercise test (TET) and a decrease in the maximum heart rate after oral
metoprolol treatment were noted. Eighteen patients in the
metoprolol group had benefited symptomatically from this treatment and complaints of
dyspnea were alleviated, whereas no symptomatic relief was seen in the
diltiazem group. No significant prolongation was observed in effort times (p>0.05) of the
diltiazem group. Transmitral gradients measured via echocardiographic examination did not change (p>0.05). With respect to
oxygen uptake rates, a statistically significant decrease was determined in the
metoprolol group, whereas no difference was found in
diltiazem group. The authors conclude that
metoprolol may be useful in patients with MS and can provide symptomatic relief. They did not observe any beneficial effect of
diltiazem in these patients.