Ambulatory blood pressure monitoring: test reproducibility and its implications.

The use of data from ambulatory blood pressure monitoring has the potential to shift how we think about assessing the cardiovascular risk factor of blood pressure. Group mean 24 h, 12 h, 8 h, and hourly blood pressures for two recordings are highly reproducible. A single 24 h ambulatory blood pressure data set correlates better to echocardiographic left ventricular wall thickness than does the average blood pressure of multiple office measurements and than does a single-office visit measurement. Both blunted and excessive nocturnal declines in blood pressure have been associated with more target-organ damage than that with a normal nocturnal decline in blood pressure. Ambulatory blood pressure monitoring has proven to be an indispensable tool in development of drugs. Unfortunately, movement, environmental noise, and excessive vibration interfere with measurement of ambulatory blood pressure. The devices are less accurate for patients with dysrhythmias. False data resulting in incorrect medical decisions might be the most important problem with ambulatory blood pressure monitoring. Reproducibility of individual ambulatory blood pressure data sets is poor. For an individual patient, it might be difficult to detect white-coat hypertension, determine dipping status, and assess a drug's effect. The use of a single ambulatory monitoring record can be inadequate for diagnosing a patient as hypertensive or normotensive. Portable noninvasive ABPM devices would provide more interpretable information if they included an activity detector, a body-position detector, and facilities for performing continuous electrocardiography and measurements of blood pressure. Devices should perform accurately when someone is engaged in vigorous activity. Perhaps detection of sleep and emotional arousal would complete the requirements for an ideal monitor.