Lessons to be learned from 24-hour ambulatory blood pressure monitoring.

A number of cross sectional studies have shown that both the 24-hour average blood pressure value and the degree of 24-hour blood pressure variability bear a significant relation with the end organ damage of hypertension. Although longitudinal evidence of the clinical relevance of 24-hour ambulatory blood pressure monitoring data are scanty, the results of a recent prospective study have clearly shown the superiority of average 24 hour, daytime and nighttime blood pressure values over clinical readings in predicting the regression of left ventricular hypertrophy in treated hypertensive patients. Ambulatory blood pressure monitoring may also be useful in the evaluation of antihypertensive treatment, although the problem of whether ambulatory blood pressure is "normalized" by treatment remains still to be properly addressed. Moreover, currently employed discontinuous ambulatory blood pressure monitoring devices cannot adequately clarify the ability of antihypertensive drugs to buffer blood pressure variability. This interesting issue needs to be assessed in a more analytical fashion by means of recently developed beat-to-beat non-invasive ambulatory blood pressure recorders coupled with wide-band spectral analysis techniques.