Ambulatory monitoring of the blood pressure in evaluating hypertensive patients.

Because office (or clinic) BP measurement is susceptible to substantial variability, ambulatory BP monitoring has become a favored method of BP measurement in clinical hypertension trials. As a result of the data obtained in over 2 decades of noninvasive ambulatory BP trials, several hypertensive patient subsets have been identified (e.g., ‘white-coat’ hypertension, nocturnal hypertension, worksite hypertension). A consensus on ‘normal’ vs ‘abnormal’ ambulatory BP has not been possible to date, however, with available cross-sectional and prognostic data, clinicians are able to use ambulatory BP monitoring for medical decision-making. Methods of analysis of ambulatory BP that have withstood the test of time include measures of centrality (mean, median, mode, ranges), BP loads, area under the BP curve, and curve smoothing. Mean values of awake ambulatory BP < mmHg in the untreated state are associated with very low indexes of hypertensive vascular disease and reduced rates of cardiac events (in contrast to patients whose awake BP exceeds mmHg). Recent studies suggest that patients in whom BP does not fall during sleep have increased hypertensive target organ morbidity and therefore are a hypertensive subgroup highly suited for ambulatory monitoring of the BP. Studies that have examined physiciansʹ practice habits in ordering and utilizing ambulatory BP monitoring demonstrate appropriate diagnostic utility of the test, an impact of the data on patient management, and potential cost-effectiveness.