Measurements of blood pressure in the clinic give an approximate indication of your blood pressure levels. More accurate information comes from home blood pressure recording by you. However, the most accurate and informative method currently is ambulatory blood pressure monitoring (ABPM). This provides a record of your blood pressure every 5 or 10 minutes during the day and night. The information is averaged to give the 24-hour blood pressure "load". Importantly, blood pressure normally should go down at night when you are asleep. This "nocturnal dip" in blood pressure is a healthy finding. The absence of a nocturnal dip, even in somebody with otherwise normal blood pressure, is a cardiovascular risk factor. The only way in which to record this dip is by ambulatory blood pressure monitoring.
Some patients have very fluctuating levels of blood pressure. Sometimes this is due to taking drugs, either for high blood pressure or for another condition (for example, Parkinson's disease). In these cases, a single recording of blood pressure during the day gives little insight into whether or not the blood pressure is adequately controlled. Other patients have an artificial rise in blood pressure when it is taken in the office. This is called "office" or "white coat" hypertension. It can lead to misleading conclusions that the patient has more severe hypertension than is the case and lead to unnecessary treatment.
These are some of the reasons why your physician may recommend that you have an ambulatory blood pressure monitor undertaken.
Please recognize that not all insurance companies reimburse you for this procedure. Therefore, you must be prepared to pay the cost of the procedure which currently is approximately $235. However, the situation is changing, and currently Medicare usually covers this as a reimbursable expense, as do many, but not all, insurance companies. Examples of insurance companies that generally cover the costs of the test are: First Health, Cigna, United Healthcare and Tricare for Life/Medicare supplement, and Alliance.
To have an ambulatory blood pressure monitor undertaken, visit the Division of Nephrology and Hypertension on the sixth floor of the Pasquerilla Health Care Building. Please call ahead to (202) 444-9183 and book a time for the measurement. Ask to speak with our receptionist.
When you come to the Nephrology Division, let the receptionist know that you wish to have an ambulatory blood pressure monitor undertaken. You will have a cuff fitted around your arm. The tubes will be connected to a small instrument similar to a cell phone clipped to your belt. You will be given instructions about how to start the instrument. Once it is started, it should be left to run continuously for 24 hours. Interrupting it, although permissible for taking a shower or some other activity, is best avoided so that we can have an accurate picture of the blood pressure throughout the whole of a 24-hour period. During this time, it is not possible to undertake strenuous activity such as jogging or playing sports. The instrument should be taken off your belt when you go to bed but must remain connected and switched on so as to record the blood pressure during your sleep. Most people find it quite possible to obtain a normal night's sleep with the instrument working.
After 24 hours, return to the Division of Nephrology and bring the instrument with you. We will print out the record. We will make a report in a few days that will be sent to you and your physician. You may wish to discuss the results with your physician at this time, to determine if you need therapy, or a change in existing therapy.