Pulse wave velocity in normotensive and hypertensive pregnant women at University Teaching Hospital (UTH), Lusaka, Zambia

Abstract

Background: Hypertensive disease in pregnancy continues to be one of the leading cause of maternal death. Pregnancy induced hypertension (PIH) is said to be accompanied by several cardiovascular pathophysiological changes including increases in arterial stiffness. Pulse wave velocity (PWV) is the method for measuring arterial stiffness. Both the pulse wave form and the velocity are said to change in PIH. However, studies documenting these characteristics of PWV have mainly been in the Caucasian population. Aims & Objectives: To establish the characteristics of PWV in normotensive and hypertensive pregnant women at the UTH in Lusaka, Zambia. Methodology: This cross-sectional study comprised of 34 systemically selected pregnant women between the ages 18-45 years old who met the criteria. A structured interview was used to collect socio demographic data. Participants’ weights and heights were then measured. After a 15 minute rest, peripheral systolic and diastolic BP were measured using an Omron M6 comfort automatic BP monitor. The PWV measurement involved applying non-invasive piezoelectric sensors over the skin after palpating for the carotid artery on the neck and the radial artery on the wrist (carotid-radial segment C-R PWV); and for the carotid-femoral segment (C-F PWV) palpation was donefor the carotid artery on the neck and the femoral artery on the inner thigh. Using IBM® SPSS® version 20.0, analyses included: kruskal-wallis, mann- whitney tests and spearman correlation tests. A 95% confidence interval (CI) and P-value of < 0.05 were set. Results: Quality recordings were obtained from C-R PWV process (p=0.041) between normotensive and hypertensive participants. There were significant increase in AP indicating an increase in pressure difference from the systolic shoulder to its peak (p=0.046). There is also a significant increase in Aix indicating an increase in arterial stiffness (p=0.031). This is further supported by a significant difference in PWV. Results from the C-F procedure experienced severe anatomical influences of the pregnant uterus and should therefore be ignored. Conclusion: Distinct differences were seen in the waveform and PWV amongst individuals with PIH. This supports the vascular changes said to take place in PIH. Thus, PWV can be used as a measure for arterial stiffness and in the screening of PIH and possible treatment