[The clinical utility of the automatic ambulatory recording of the arterial pressure in the diagnosis, prognosis and treatment of arterial hypertension].

Ambulatory blood pressure monitoring (ABPM) is, nowadays, one of the most powerful medical tools, in the evaluation of blood pressure (BP) behaviour during a normal daily life, particularly in hypertensive patients, and to assess with a high level of accuracy, the antihypertensive effectiveness of the pharmacological compounds. In this paper, we present the main indications and limitations of the method, and a new circadian classification of arterial hypertension based on an average deviation index (ADI), resulting of the addition of all the systolic and diastolic ambulatory measurements exceeding 140/90 mmHg recorded along the 24-hour extrahospital monitoring, and dividing the result by two. The study was carried out in 939 hypertensive patients diagnosed by means of basal blood pressure measurements (BP > 140/90 mmHg), and in 45 normal volunteers. Hypothetically, this ADI may vary only from 0 (normal curve) to 100% (complete abnormal circadian curve). From ADI 0 to 100, we have established 4 categories of circadian curves as follows: curve 0 or "normal" if the ADI varies from 0 to 5%, curve type I or "borderline" (white coat phenomenon) if ADI moves between 6 and 30%, curve type II or "diurnal" if the ADI varies from 31 to 65%, and finally curve type III or "sustained", if the ADI goes further on than 66%. The results indicate clearly a high percentage of white coat hypertension (30%) where 4% showed an ADI less than 5%. A half approximately of the patients showed diurnal hypertension, and a quarter of them, both diurnal and nocturnal hypertension, so-called sustained hypertension. 75% of all the hypertensive patients showed spontaneous normotensive values at nighttime.(ABSTRACT TRUNCATED AT 250 WORDS)