title: The effects of postural changes of baroreflex gain in normal and hypertensive pregnancies.
abstract: In order to understand the changes of baroreflex gain due to postural changes in normal pregnancies, we measured percentage changes (% changes) in blood pressure (SBP, DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) as well as cardiac autonomic nervous function (HF as an index of parasympathetic and LF/HF as an index of sympathetic function) and compared these parameters in normal pregnancies with those found in hypertensive pregnancies, such as chronic hypertensive (CHP) and severe preeclamptic pregnancies (PE), in late pregnancy (after 32 wks). When the position was changed from supine to standing in normal and non-pregnant women, the % changes of HR, DBP, TPR and LF/HF were increased and SBP, SV, CO and HF were decreased. The % changes of these parameters, however, were gradually decreased as pregnancy progressed, especially after 20-24 wks of gestation. In hypertensive pregnancies, however, even in late pregnancy, the decreased SBP and increased TPR was still observed and the profound decrease of CO and SV and increase of TPR were characteristic in PE when compared to CHP.
authors.affiliation: Nihon University School of Medicine, Nerima Hikarigaoka Hospital, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Miyake
authors.forename: Miyako
authors.initials: M
authors.lastname: Ohnishi
authors.forename: T K
authors.initials: TK
authors.lastname: Fujii
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Chika
authors.initials: C
authors.lastname: Yoneda
authors.forename: Sachie
authors.initials: S
authors.lastname: Takahashi
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Ichimaru
mesh_terms: D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008137:Longitudinal Studies; D011187:Posture / Q000502:physiology*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000503:physiopathology*; D012016:Reference Values