[Automated ambulatory 24-hour monitoring of blood pressure in hypertensive patients].

: In order to analyse the 24 h blood pressure pattern, a non-invasive 24 h ABPM was recorded in 18 normotensives (23-44 years) and in 24 untreated essential hypertensives (28-65 years) using a Space-Labs 90202. This device was previously validated with a mercury sphigmomanometer (S) and with intraarterial blood pressure (IA). The correlation coefficient obtained for systolic blood pressure (SBP) between ABPM and IA was 0.89, p less than 0.0001 and between ABPM and S was 0.98, p less than 0.0001. Likewise, a significative correlation for diastolic blood pressure (DBP) was found between ABPM and IA (r = 0.78, p less than 0.0001) and between ABPM and S (r = 0.97, p less than 0.0001). Essential hypertensives showed higher mean values of SBP and DBP than normotensives (p less than 0.01) maintaining a similar circadian pattern. In these patients, the percentages of mean abnormal SBP (greater than 140 mmHg) and DBP (greater than 90 mmHg) readings were greater than 58% and 56% for the 24 h period, and 70% and 77% for the activity period, respectively. On the other hand, in normotensives the percentages of mean abnormal SBP and DBP readings were lower than 10.5% and 5.7% for the 24 h period, and 17.2% and 11.7% during the activity period, respectively. In conclusion, 24 h ABPM enabled us to characterize two well differentiated populations either by mean BP values of the percentages of abnormal readings. Between normotensives and hypertensives an intermediate group of subjects, with normal mean BP values and higher percentages of abnormal BP readings than normotensives remains to be characterized and longitudinally studied in order to evaluate their target organ repercussion.