A New Role for Ambulatory Blood Pressure Monitoring?

It has been known for more than 50 years that the blood pressure (BP) of hypertensive patients measured in a medical setting such as a physician's office tends to be higher than in other settings.¹ With the introduction of noninvasive ambulatory BP monitoring, researchers showed that about 20% of patients hypertensive in the physician's office have normal BPs outside the office, a phenomenon usually referred to as white coat hypertension.² Whether such patients should be given antihypertensive medication remains controversial, but most experts believe that the best policy is simply to monitor their BP on a regular basis, both in and out of the office.³ There is also evidence that if patients with white coat hypertension are started on medication, the office BP is reduced but not the BP during the rest of the day.⁴ Ambulatory monitoring so far has been used in clinical practice principally