Ambulatory BP monitoring
Ambulatory BP monitoring is a diagnostic test that is done to determine the presence of hypertension by taking measurements during normal daily activities, over a span of 24 consecutive hours.
Some facts about Ambulatory BP monitoring:
- Ambulatory BP monitoring helps to diagnose and monitor high blood pressure
- Usually high blood pressure is defined as a systolic pressure of 140 mm Hg or more and a diastolic pressure of 90 mm Hg or more.
- The instrument used to measure blood pressure is a portable blood pressure machine worn as a belt, with the cuff being attached around the upper arm.
- Normally, all types of daily activities, including sleep, may be carried out while wearing this device.
- ABPM is also useful in monitoring borderline hypertension, fluctuating hypertension, refractory hypertension, surveillance of pregnancy with hypertension, change of medications for hypertension to monitor changes in the blood pressure as a result.
- Unnecessary prescribing of hypertension can be prevented by giving an accurate picture of a patient’s blood pressure throughout the day and during sleep, reducing drugs for white coat hypertension.
Importance of a 24-Hour Measurement of Blood Pressure:
- Regular blood pressure readings are taken during the ABPM, for several reasons.
- The normal variations in blood pressure are monitored in this test.
- The 'white coat effect' can be eliminated, which means that blood pressure measurements taken by a doctor in a clinic are on average 9/7 mm Hg (systolic/diastolic pressure) higher than corresponding readings taken by a nurse or other trained practitioner in the same setting.
- Masked and sustained hypertension can be detected.
- It is termed ‘masked hypertension’ when the blood pressure reading is normal in the clinic but high during normal activity, whereas a persistently high blood pressure is called sustained hypertension and is associated with higher risk of heart attacks and renal injury
- The normotensive effect of current medications can be shown, which is the effect of medications on controlling the blood pressure throughout the day.
- When the blood pressure increases at night or during sleep, a phenomenon seen in some individuals can be revealed.
- This may need an adjustment in the medical regimen.
- The heart rate can be shown at the same time.
- The average or mean blood pressure, heart rate and a few other parameters can be produced.
- The chances of stroke or heart attacks can be predicted.
Working of ABPM:
- The ABPM monitor is attached at the outpatient clinic and readings are taken at about every 15 to 30 minutes throughout the day and every half hour to one hour at night.
- The cuff is worn throughout the period and the machine is kept under the pillow or besides the patient on the bed during sleep.
- The patient must not change the normal routine to get a more accurate picture of how the blood pressure changes with various phases of daily activity.
- All the readings which are analyzed can be stored once it is removed and taken back to the clinic or hospital.
- The machine utters a warning beep when a reading is about to be taken.
