Ambulatory Blood Pressure Monitoring

Ambulatory Blood Pressure Monitoring is a test where your blood pressure and heart rate are taken at a fixed time interval for 24 hours while you continue with your daily activities.

It is particularly useful for patients with high blood pressure as it helps your doctor determine if your blood pressure medications are effective. It is also used to monitor borderline hypertension, young hypertension and poor blood pressure control. This 24-hour monitoring allows the doctor to study the variations of your blood pressure throughout the day.

Is the test safe?

There are no direct risks involved in this test. However, some patients may get some discomfort and skin irritation due to the prolonged use and compression of the blood pressure cuff as well as the prolonged use of tapes to secure the blood pressure tubing.

How is the test done?

The Cardiac Physiologist/Technologist will first take your height and weight to determine your body mass index (BMI). Blood pressure readings will be taken on both arms to determine your baseline blood pressure. Thereafter, you will proceed to a private room to have the portable blood pressure device fixed on you.

The Cardiac Physiologist/Technologist will then measure the length and circumference of your arm to provide you with the most suitable blood pressure cuff for the portable blood pressure device. There will be three manual blood pressure readings taken and recorded. The machine will then be calibrated for your use. During daytime, the machine is programmed to measure your blood pressure every 20 minutes. After 10pm, the frequency is reduced to one blood pressure taking every 30 minutes. When your blood pressure is being taken, you are advised to stop all motions (if possible) as well as avoid bending the arm (with the cuff).

During this period, you can continue with your normal daily activities (except for showering and vigorous exercise). You must not remove the blood pressure cuff during this recording period. To ensure accuracy of the recorded results, the Cardiac Physiologist/Technologist will advise you on the adjustment of the cuff should it come loose. You are also required to note down the time you go to bed and the time you wake up in the diary provided to you.

If there are insufficient (less than 50% successful) recordings throughout the test, your doctor may request for a repeat of the test.

Preparations before the test

• Take a bath and wear loose fitting clothing before coming for the appointment. You will not be able to shower during the duration of the test (24 hours).
• No fasting is required.
• No admission is required.
• You may continue with your current medication (unless advised otherwise).
• You will need to return the device the next day (please consider taking leave if necessary as no medical certificate will be provided on the removal day).