[The diurnal rhythm of the arterial pressure in normal pregnancy and in hypertension]. / Ritmo diario de tensión arterial en el embarazo normal y con hipertensión.

An alteration upon the daily rhythm of blood pressure in patients with gestational hypertension has been reported, albeit inconsistently. Hence we have evaluated the daily rhythm of blood pressure in women with normal gestation (n = 100) and with pregnancy associated hypertension (n = 111). In an attempt to delineate a possible etiology of the hypertension, patients were subdivided according to a classification of the American College of Obstetricians and Gynecologists. (Group I. Preeclampsia-eclampsia; group II. Chronic hypertension; group III. Chronic hypertension with superimposed preeclampsia; group IV. Late gestational hypertension). Blood pressure quantitation was made with sphygmomanometer and by different observes. Those with normal pregnancy showed a higher increase in both systolic and diastolic pressure in the morning with a peak at 1200 H, that contrasted with a very low level registered at 2400 H. Altogether the hypertensive group exhibited a loss of rhythm; whereas by group: in I. There was absence of rhythm without a predominant pattern; II. & III. An increase of systolic pressure which was accetuated at 0600 H. group IV. Showed the lowest tensional levels without special characteristics. Through these data, it seems that the central nervous system loses control upon daily regulation of blood pressure in preeclamptic women.