The Study Of Vascular Function And Mechanical Features In Pregnancy-Induced Hypertension Using High-Resolution Ultrasound

Objective:1) To evaluate brachial artery flow-mediated vasodilation (BA-FMD) in patients withpregnancy- induced hypertension (PIH) using high-resolution ultrasound(HRUS).2) To evaluate the longitudinal velocity, strain and strain rate of the of common carotid artery in pregnancy-induced hypertension patients by a novel, angle-independent, feature-tracking method-echocardiographic Velocity Vector Imaging (VVI).Methods:1) Twenty-five PIH patients, twenty-five normal pregnant(NG) women ( control group1) and thirty healthy non-pregnant women (control group2) were enrolled in this study and BA-FMD was measured by high-resolution vascular ultrasound.2) Twenty-eight PIH patients,with thirty-four normal pregnancy women as the control group, were enrolled in this study, Long-axis view of the common carotid arteries were acquired . The maximum systolic velocities (Vs), maximum strains (Smax) and maximum strain rates (SRmax) of the anterior and posterior walls of the common carotid arteries were measured.Results:1) After reactive congestion of brachial artery, the diameters of brachial arteries significantly increased in all the three groups. In comparison to the control groups, the percentage of diameter change of brachial artery significant decreased in the PIH patients (P< 0. 001;P< 0.001). But the percentage of diameter change of brachial artery in normal pregnancy women group is higher than that in healthy group( P < 0.05) .2) In comparison to the normal pregnant women group, the maximum velocities of the anterior and posterior walls of the common carotid arteries in the long axis view in PIH group significantly decreased ( P< 0.01;P< 0.01). And there were differences in the Smax of the anterior and posterior walls of the common carotid arteries between the PIH and the NG group ( P< 0.01;P< 0.05) . And SRmax had significant differences in cmmon carotid arterial long axis walls (anterior and posterior wall)in PIH group and the control group (P< 0.05; P< 0.05). Conclusions:1) The endothelium-dependent vasodilatation function significantly decreases in the PIH group, and the high-resolution ultrasound can be an effective way of assessing the brachial artery endothelial function.2) The maximum velocities,strains and maximum strain rates of the anterior and posterior walls of the common carotid arteries significantly decreased, and VVI can be a promising clinical tool for assessing the vascular function in PIH.