Systemic and Arterial Hemodynamic Effects of Nifedipine (20 mg) in Mild-to-Moderate Hypertension

SUMMARY Systemic and arterial hemodynamic effects of the new 20 mg tablet of nifedipine were studied in seven patients with mild-to-moderate essential hypertension. Hemodynamics of the fore-arm arterial circulation were investigated using a new pulsed Doppler system, enabling the simulta-neous determination of the brachial artery diameter and the arterial blood flow velocity. After nifedipine administration, blood pressure decreased significantly, due to a fall in total peripheral resistance. Simultaneously, brachial blood flow increased significantly, due both to an increase in arterial diameter and blood flow velocity. The study provided evidence that, with nifedipine, there is both 1) a dilation of small arteries, causing a decrease in blood pressure; and 2) a dilation of peripheral large arteries, leading to an increase in peripheral blood flow. (Hypertension 5 (supp V): V-57-V-60, 1983) KEY WORDS • essential hypertension peripheral blood flow calcium antagonists • pulsed Doppler THE antihypertensive effect of the calcium-channel blocker, nifedipine, is well estab-lished.1 Most studies indicate that the 10 mg tablet given orally causes a rapid decrease in bloo