The effect of metoprolol on left ventricular systolic and diastolic function in essential hypertension.

Using ultrasound techniques, parameters of left ventricular systolic and diastolic function were assessed in 23 patients with degree I-II essential hypertension treated with metoprolol. Metoprolol administration was followed by increases in ejection fraction (p less than 0.01) and stroke volume (p less than 0.05), a decrease in heart rate (p less than 0.01) while cardiac output remained unchanged. Left ventricular filling was abnormal in 12 patients (52.2%). After metoprolol, the ratio of early diastolic to late diastolic transmitral velocity (E/A) rose; the increase indirectly correlated both with the baseline value of E/A (r = -0.59, p less than 0.01), and the change in heart rate (t = -0.65, p less than 0.01). Improved left ventricular diastolic filling was significant only in patients showing abnormal baseline diastolic function, and may be due to the decrease in heart rate rather than a direct effect exerted by metoprolol on the myocardium.