Twenty-four-hour blood pressure monitoring, also called ambulatory blood pressure measurement, records blood pressure automatically at regular intervals over a full day and night while the patient goes about ordinary activities. It gives a far more reliable picture than isolated readings taken in a consulting room.
Why a single reading is not enough
Blood pressure varies continuously with activity, stress, sleep and time of day. Some people record high readings in a medical setting but normal values elsewhere; others record normal values in clinic while their blood pressure remains high the rest of the time, including overnight. Ambulatory monitoring distinguishes between these situations and shows the night-time pattern, which is one of the more informative parts of the recording.
What it is used for
- Confirming or excluding a diagnosis of hypertension before treatment is started.
- Checking whether existing treatment is controlling blood pressure over the whole day.
- Investigating symptoms such as dizziness that may reflect blood pressure falling too low.
- Assessing blood pressure during sleep.
How it works
A small monitor is worn on a belt and connected to a cuff on the upper arm. The cuff inflates automatically, typically every fifteen to thirty minutes during the day and less often at night. The patient keeps to a normal routine, keeps the arm still and relaxed during each measurement, and notes the times of sleep, medication and any symptoms. The device is returned the following day and the recording is analysed by the cardiologist.
Practical points
Wear a loose-sleeved top so the cuff sits directly on the upper arm. The monitor must not get wet, so showering is not possible while it is fitted. The night-time inflations do interrupt sleep for some people; this is expected and does not invalidate the recording.
Reimbursement
Ambulatory blood pressure monitoring is listed in the CNS nomenclature and is reimbursed under the national health insurance scheme, at 88% for adults and 100% for patients under 18.