Procedures

Diagnosis of “White Coat Hypertension” — blood pressure is normal when measured at home but high when taken by a nurse or doctor.

Detecting abnormal BP patterns — normally BP falls when you are asleep. If the BP does not fall or actually rises during sleep, hypertension is more likely to be associated with other heart and non-cardiac conditions, such as heart failure, kidney failure or autonomic neuropathy. This pattern is more common in patients who have a reversible cause of high blood pressure.

Monitoring effects of treatment — the variation in blood pressure during daily life makes measuring the effect of lifestyle changes or drug treatment very difficult. The ABP is the most reliable way of measuring this and allows more accurate comparisons of BP over time.

A standard arm cuff of an appropriate size is put on your arm by one of our technicians. It is fitted around the upper arm directly over the pulse. It is fastened with a Velcro fastener and turned on. This is usually put on your non-dominant arm- the opposite to the one used in writing- and attached to a small battery-powered pump and recorder. The pump inflates the pressure to above your maximum (systolic) blood pressure and gradually releases the pressure to below the minimum (diastolic) blood pressure in time with the pulse.

There is no need to fast and you should continue all other activities. It is very important that we know what medications are being taken at the time we do the test. An easy way is to bring all your medications with you to the first appointment.

The cuff, connecting tubing and pump are usually hidden under normal clothing but sleeves need to be relatively loose. The appointment time takes about 20 minutes.

You cannot bathe or shower during the test as the device is not waterproof. You should take part in all other life activities. When driving a car or doing any other activity where cuff inflation could be distracting, it may be preferable to turn off the device temporarily.

Normally the recorder is removed in our office but it can be removed, switched off and brought to the office by someone else for you if that is more convenient. However, we do need to know what time you went to sleep and what time you woke up during the ABP recording. We may well ask you about times of the day when blood pressure spikes or is unusually low and if so what you were doing at the time such as watching TV or having a nap for example.

There are no known serious risks from having a BP monitor. Occasionally people will get skin irritation from the cuff but this resolves after they are removed. Depending on the blood pressure, the cuff can inflate to a high point which can cause localise bruising.