Ambulatory blood pressure monitoring: guidelines for use in clinical practice.

Ambulatory blood pressure monitoring is rapidly becoming an integral part of the diagnosis and management of hypertensive patients, particularly in major urban Canadian centres. To date, there have been several attempts to define the indications for ambulatory blood pressure monitoring, the most recent coming from an ad hoc panel of the American Society of Hypertension. This panel developed an algorithm for diagnosing persistent hypertension using office, home and ambulatory blood pressure readings. A revised algorithm tailored to the Canadian health care setting is proposed for implementing ambulatory blood pressure monitoring in the diagnosis of hypertension. Concerns about the term 'white coat' hypertension are discussed and the concept of a white coat effect for both untreated and treated patients is presented. There is preliminary evidence that patients who have a white coat component to their office readings experience fewer cardiovascular outcomes than do those with more persistent ambulatory hypertension. Recommendations from the ad hoc committee of the American Society of Hypertension provide a practical basis for using ambulatory blood pressure monitoring in clinical practice in Canada.