To assess flow-mediated dilation in the radial artery noninvasively using a newly developed 30-MHz mechanical linear probe.
Twenty-six normal pregnant women and 16 nonpregnant healthy women were assessed.
Longitudinal images of the radial artery clearly showed the three layers of the vessel walls. A cuff placed on the upper arm was inflated to 30 mmHg above systolic pressure for 5 minutes. The diameter of the radial artery was measured before inflation (baseline) and after deflation of the cuff. Imaging of the artery was conducted for 6 minutes after the cuff was deflated. Flow-mediated vasodilation was determined by measuring change in radial artery diameter, expressed as a percentage of baseline diameter.
Maximum vasodilation occurred 1 minute after the cuff was deflated. Flow-mediated vasodilation in pregnant women (18%±6%) was significantly greater than in nonpregnant women (12%±4%, p
Greater vasodilation in pregnant women than in nonpregnant women is thought to be influenced by improvement in
endothelial function. The procedure used here is noninvasive, and repetitive examination is possible. This procedure makes
early detection and classification of pregnancy-induced hypertension accompanied by reduction in endothelial function possible.