Predictable blood pressure variability in clinically healthy human pregnancy

D.E. Ayala, R.C. Hermida
[1991] Computer-Based Medical Systems@m_Proceedings of the Fourth Annual IEEE Symposium  
Conventional time-unspecijied single measurements of blood pressure {BP) and heart rate {HR) may be misleading since they may be influenced, among other factors, by the patient's emotional state, position, diet, and external stimuli. All of these effects depend upon the stages of a (mathematical) spectrum of rhythms and trends with age. The evaluation of predictable variability in BP and HR by I ) the use of fully ambulatory devices, and 2 ) chronobiologic data processing, assesses early
more » ... ascular disease risk, e.g., in pregnancy. We have used this approach to quantify changes in 24-hour synchronized (circadian) characteristics of BP and HR in two consecutive pregnancies of a clinically healthy woman (DEA). BP and HR were automatically monitored, with few interruptions, at I-hour intervals, and for a total of 76 days days of monitoring in each pregnancy. Circadian parameters of BP and HR were computed for each single day of measurement by the least-squares fit of a 24-hour cosine curve. Regression analysis of parameters thus obtained revealed patterns of variation of circadian rhythm-adjusted means and amplitudes with gestational age. This longitudinal study confirms and extends to ambulatory everyday life conditions the predictable pregnancy-associated variability in BP and HR and also allows the establishment of prediction and confidence limits for cardiovascular parameters in a healthy pregnancy.
doi:10.1109/cbms.1991.128942 dblp:conf/cbms/AyalaH91 fatcat:gmghjnzyrzberderslf3a7p3v4