Diurnal blood pressure variation in the evaluation of early onset severe pre-eclampsia

Postpartum Detection of Diastolic Dysfunction and Nondipping Blood Pressure Profile in Women With Preeclampsia

BACKGROUND

Left ventricular diastolic dysfunction and nocturnal "nondipping" of blood pressure detected via ambulatory blood pressure monitoring are predictors of increased cardiovascular morbidity.

METHODS

A prospective cohort study including normotensive women with a history of preeclampsia in their current pregnancy was conducted. All cases were subjected to 24-hour ambulatory blood pressure monitoring and 2-dimensional transthoracic echocardiography 3 months after delivery.

RESULTS

This study included 128 women with a mean (SD) age of 28.6 (5.1) years and a mean (SD) basal blood pressure of 123.1 (6.4)/74.6 (5.9) mm Hg. Among the participants, 90 (70.3%) exhibited an ambulatory blood pressure monitoring profile illustrating nocturnal blood pressure "dipping" (the mean night to day time blood pressure ratio ≤ 0.9), whereas 38 (29.7%) were nondippers. Diastolic dysfunction (impaired left ventricular relaxation) was present in 28 nondippers (73.7%), whereas none of the dippers exhibited diastolic dysfunction. Women with severe preeclampsia were more frequently nondippers (35.5% vs 24.2%; P = .02) and experienced diastolic dysfunction (29% vs 15%; P = .01) than were those with mild preeclampsia. Severe preeclampsia (odds ratio [OR], 1.08; 95% CI, 1.05-10.56; P < .001) and history of recurrent preeclampsia (OR, 1.36; 95% CI, 1.3-4.26; P ≤ .001) were significant predictors for nondipping status and diastolic dysfunction (OR, 1.55; 95% CI, 1.1-2.2; and OR, 1.23; 95% CI, 1.2-2.2, respectively; P < .05).

CONCLUSION

Women with a history of preeclampsia were at higher risk for developing late cardiovascular events. The severity and recurrence of preeclampsia were significant predictors of both nondipping profile and diastolic dysfunction.

Physiology of blood pressure relevant to managing hypertension in pregnancy

PURPOSE

Pregnancy causes physiological changes in maternal organ systems, and blood pressure (BP) is one of the variables affected. This review is focusing on the physiology of BP relevant to the management of hypertension in pregnancy.

MATERIALS AND METHODS

A detailed literature search was performed using electronic databases (including WorldCat, PubMed, MEDLINE, Google Scholar) to retrieve and review reports related to physiology of BP in pregnancy.

RESULTS

During pregnancy, there is vasodilation caused by mediators such as increased levels of progesterone and nitric oxide. The vasodilation leads to a reduction in vascular resistance, BP, and renal blood flow. In compensation, the following postulated events occur: activation of renin-angiotensin-aldosterone axis, resetting of osmotic threshold for thirst, and an increase in the production of vasopressin. Sodium and water conservation ensue to increase the total body water, end-diastolic volume, cardiac output, and BP. The increase in cardiac output incompletely compensates for the decreased vascular resistance, and BP therefore decreases in midpregnancy and returns to prepregnancy level toward term.

CONCLUSIONS

An understanding of the physiological changes in BP is essential for appropriate management of pregnancy-related hypertension.