Commentary

Excerpt

In his review O’Brien [1] makes a powerful case for the wider use of ambulatory blood pressure monitoring in clinical practice and research. He highlights the wealth of data that can be obtained from a single 24-h recording, and emphasizes the essentially dynamic nature of blood pressure, which is the result of the daily cycle of rest and activity. It is becoming widely accepted that ambulatory pressure gives a better prediction of risk in hypertensive patients than conventional measurements, but as O’Brien describes, there are numerous components or “windows” of the diurnal profile of blood pressure, each of which has been claimed to have its own prognostic significance. From a clinical point of view, the finding that the average level of BP over the entire 24 h period is high is sufficient to identify the patient as being at increased risk. Conversely, the finding that the ambulatory pressure is normal despite a high clinic pressure (white coat hypertension) may mean that the patient does not require drug treatment. This is so far the only indication that has been accepted for reimbursement by Medicare in the USA. Most of the windows that O’Brien discusses are of greater interest in clinical research than practice at the present time. He introduces two new terms—Vesperal and Basal Windows. The former is the early part of the night, when people are typically on their way to bed, and when the pressure is on its way down to the nadir, or Basal Pressure. …