Ambulatory Blood Pressure Monitoring (ABPM) is a test done to record your blood pressure at fixed intervals throughout a 24 hr period while you move around, living your normal everyday life. It uses a small blood pressure machine that is attached to a belt around your body and is connected via a tube to a cuff wrapped around your upper arm. It is small enough not to obstruct normal daily life while you can even sleep with it on.
Why do it:
By measuring blood pressure at regular intervals over 24 hours, your doctor is able to get a clear picture of how the blood pressure fluctuates throughout the day and night. There are a number of reasons why your doctor might suggest this test:
• To confirm if you do suffer from high blood pressure and how high are the readings over a 24 hr period.
• If your blood pressure readings are always high in doctors clinic/ surgery, your doctor may want to know if blood pressure is actually lower outside the clinic – this is called the “white coat effect”.
• Your doctor may want to see how big are the fluctuations in your blood pressure throughout the 24 hr period.
• To see how well the medicines are working, and to make sure they are controlling your blood pressure throughout the day and night.
• To see if your blood pressure stays high at night. If this is the case, your doctor may want to change or adjust your medicines.
• You need to be booked for this test and there may be a small fee charged as this test is still not reimbursed by Medicare in Australia.
• The blood pressure cuff is wrapped and fixed around your upper arm – either arm can be used.
• The digital blood pressure machine itself is attached to a belt around your waist.
• Technician checks that battery life is sufficient for 24 hrs and checks if the machine operates well.
• The cuff inflates every 30-60 minutes as per the settings and then slowly deflates to record the blood pressure in its memory. This is no different from any other blood pressure machine.
• The blood pressure is recorded throughout the 24 hr period. Please do not switch it off at night as night time readings are equally important.
• Normally the machine is fitted at your local hospital outpatients department, although some GP surgeries may have their own.
• Because the test is being carried out to find out what your normal daily blood pressure is, it is important to carry on with your normal routine and do all the things you would normally do.
• To allow the machine to work properly, it is important to make sure that the tube from machine to the cuff is not twisted or bent.
• Just before the machine is about to take a reading, it will beep. When this happens you should try to relax, keep your arm steady and sit down if possible.
• You will also be asked to keep a diary of what you were doing just before the reading was taken, what time you went to sleep and what time did you get up in the morning.
• Some people find 24-hour ABPM distracting and uncomfortable: if you feel like this when the readings are being taken, please tell your doctor about this as it may affect your readings.