Hyperemic Response of the Brachial Artery During the Second Half of Pregnancy

Abstract

Objective: To determine if women who developed preeclampsia had measurable differences in the vascular response postrelease of a 1-minute blood flow occlusion.

Methods: A total of 33 nulliparous patients were enrolled in this study during the second half of the pregnancy. All had baseline Doppler flow velocities while resting in the left lateral decubitus. Subsequently, a blood pressure cuff was inflated for 60 seconds in the forearm so as to occlude blood flow. Doppler waveforms were analyzed immediately after the release of the blood pressure cuff and on a single beat occurring at 15 second intervals for a total of five reading. After a rest period, patients were asked to squeeze a handheld manometer at maximum strength as long as possible. Doppler waveforms were analyzed as above. The Doppler waveforms of all enrolled patients who subsequently developed preeclampsia any time after the study were compared to those who remained normotensive.

Results: 1) The “hyperemic response” that occurred immediately after release of the blood pressure occlusion of the forearm was significantly different between patients who subsequently developed preeclampsia compared with those who remained normotensive, 2) the hyperemic response that occurred after the isometric handgrip exercise was not significantly different between the two groups, and 3) sensitivity, specificity, and negative predictive values were high, but positive predictive values were low.

Conclusion: There was a significant difference in the hyperemic response of the brachial artery to a short period of ischemia of the foream (blood pressure occlusion) between normotensive patients and a group of patients who subsequently developed preeclampsia.