Abstract
To evaluate the effect of metoprolol, a β1-selective adrenoreceptor blocking agent, on the circadian rhythms of blood pressure (BP) and heart rate (HR), ambulatory BP and HR monitoring was performed in subjects with essential hypertention before and 4wk after the treatment. BP and HR were measured with ABPM-630 (Colin, Japan) every 30min for 48hr, and were analyzed by conventional statistic method, cosinor method and Fourier transformation.
The circadian patterns of systolic BP and diastolic BP were not affected by metoprolol while its antihypertensive effect was confirmed.
However, the circadian rhythm of HR was significantly depressed by metoprolol. It was suggested that the circadian rhythm of BP would be preserved through the modulatory role of HR after metoprolol.
These findings indicate the importance of the individualization of effects of antihypertensive agents on the circadian rhythms of BP and HR.
