Circadian Time Structure of Cardiovascular Characteristics in Human Pregnancy

Conventional time-unspecified single measurements of blood pressure and heart rate may be misleading because they may be influenced, among other factors, by the patient's emotional state, position, diet, and external stimuli. All of these effects depend on the stages of a (mathematical) spectrum of rhythms and trends with age. The evaluation of predictable variability in blood pressure and heart rate by (a) the use of fully ambulatory devices, and (b) chronobiologic data processing, assesses early cardiovascular disease risk, e.g., in pregnancy. We have used this approach to quantify changes in 24-h synchronized (circadian) characteristics of cardiovascular variables in two consecutive pregnancies of a clinically healthy woman. Blood pressure and heart rate were automatically monitored, with few interruptions, at I-h intervals, each time for at least 48 consecutive h, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of those circulatory variables were computed for each single day of measurement by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian-rhythm-adjusted means and amplitudes with gestational age. In both pregnancies, the predictable variability of the circadian-rhythm-adjusted mean of blood pressure can be approximated by a second-order polynomial model on gestational age: a steady linear decrease in systolic, diastolic, and mean arterial blood pressure up to the 22nd week of pregnancy is followed by an increase in blood pressure up to the day of delivery. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure and heart rate and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.     

Circadian Time Structure of Cardiovascular Characteristics in Human Pregnancy

Conventional time-unspecified single measurements of blood pressure and heart rate may be misleading because they may be influenced, among other factors, by the patient's emotional state, position, diet, and external stimuli. All of these effects depend on the stages of a (mathematical) spectrum of rhythms and trends with age. The evaluation of predictable variability in blood pressure and heart rate by (a) the use of fully ambulatory devices, and (b) chronobiologic data processing, assesses early cardiovascular disease risk, e.g., in pregnancy. We have used this approach to quantify changes in 24-h synchronized (circadian) characteristics of cardiovascular variables in two consecutive pregnancies of a clinically healthy woman. Blood pressure and heart rate were automatically monitored, with few interruptions, at I-h intervals, each time for at least 48 consecutive h, and for a total of 76 days of monitoring in each pregnancy. Circadian parameters of those circulatory variables were computed for each single day of measurement by the least-squares fit of a 24-h cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian-rhythm-adjusted means and amplitudes with gestational age. In both pregnancies, the predictable variability of the circadian-rhythm-adjusted mean of blood pressure can be approximated by a second-order polynomial model on gestational age: a steady linear decrease in systolic, diastolic, and mean arterial blood pressure up to the 22nd week of pregnancy is followed by an increase in blood pressure up to the day of delivery. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in blood pressure and heart rate and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.     

1g/h与2g/h硫酸镁维持剂量输注期间的血清镁水平预防子痫效果

摘要 目的：探究硫酸镁不同维持剂量在预防子痫中的临床效果分析。方法：选择2018年1月至2020年1月于我院接受治疗的100例子痫前期产妇,按照随机数字表法区分为研究组与对照组（每组各50例产妇）,对照组产妇接受1 g/h硫酸镁维持剂量输注,研究组产妇接受2 g/h硫酸镁维持剂量输注,对比两组产妇干预前后血压、24 h尿蛋白、血浆纤维蛋白原、尿钙黏蛋白变化,统计两组产妇临床疗效差异以及不良反应发生情况。结果：（1）研究组治疗总有效率为98.00 %,高于对照组的86.00 %（P<0.05）;（2）干预前两组产妇收缩压和舒张压组间无差异（P>0.05）,治疗后研究组收缩压和舒张压均低于对照组（P<0.05）;（3）干预前两组产妇24 h尿蛋白、血浆纤维蛋白原水平组间无差异（P>0.05）,治疗后研究组上述指标均低于对照组（P<0.05）,但两组干预前后血清镁水平无差异（P>0.05）;（4）研究组不良反应总发生率14.00 %,显著高于对照组的2.00 %（P<0.05）。结论：对子痫产妇持续输注2 g/h硫酸镁可以有效改善其临床症状,降低产妇血压水平,控制其疾病进展效果较好,但不良反应发生情况显著高于持续输注1 g/h硫酸镁的产妇。     

Relevance of the assessment of natriuretic peptide plasma concentrations in hypertensive pregnant women

Abstract

Assessment of the plasma concentrations of natriuretic peptides (NPs) is widely used to diagnose and evaluate the progression of cardiac failure, and their potential as markers of preeclampsia (PE) has been examined in recent years. It has been established that plasma concentrations of NPs do not change in the course of normal pregnancy. However, elevated levels of these peptides may have a prognostic value in patients with PE. This study presents information about the relevance of NPs assessment in the evaluation of physiological pregnancy, as well as in pregnancy complicated with arterial hypertension. The most commonly examined NPs is the N-terminal fragment of the brain natriuretic peptide (NT-proBNP), and it may be prognostic marker of PE and other complications of pregnancy.