MATERNAL BRACHIAL ARTERIAL WAVE-FORMS IN GESTATIONAL HYPERTENSION - ANALYSIS USING A LAPLACE TRANSFORM TECHNIQUE

Objective: A pilot study was designed to investigate whether maternal brachial arterial Doppler shift waveforms analyzed using a Laplace tra nsform analysis technique could distinguish women with gestational hyp ertension and preeclampsia from women who remained normotensive during their pregnancy. Methods: We examined 50 pregnant women in total. The y were divided into two groups. The first was a group of 21 normotensi ve women, and the second was a group of 29 women with gestational hype rtension or preeclampsia, not on medication at the time of study. A Do ppler shift waveform of the right and left brachial artery was obtaine d and analyzed using the conventional parameters of resistance index ( RI) and pulsatility index (PI) and Laplace transform analysis. Results : The systolic and diastolic blood pressures and the mean arterial blo od pressure at presentation were significantly higher in group 2 as ex pected. The results of the Laplace transform parameters showed signifi cant differences in the resonant frequency, real pole, c coefficient, and a between the two groups. There was no difference in the PI betwee n the two groups, but the differences in RI just reached significance. The Laplace transform parameters in the group with gestational hypert ension were consistent with peripheral vasoconstriction, which has bee n suggested as part of the hemodynamic abnormalities in this condition . Conclusion: Analysis of maternal brachial arterial Doppler shift wav eforms by Laplace transform analysis detects differences between normo tensive and hypertensive patients. These differences may also reflect some of the hemodynamic changes occurring in gestational hypertension.