The Ambulatory blood pressure monitor (ABPM) is the GOLD STANDARD for adequately and appropriately measuring blood pressure.

The Joint National Committee on Hypertension recommended the use of Ambulatory Blood Pressure Monitoring in 2003.17

In fact, you can’t properly evaluate and treat hypertension without it!

What is Ambulatory Blood Pressure Monitoring (ABPM)?

24-hour ambulatory blood pressure monitors (ABPM) measure your blood pressure in your environment. It is a portable blood pressure device that we have available in our Tulsa Functional Medicine clinic and check-out to our patients.

It consists of a blood pressure cuff (very similar to the one’s you’ve probably seen) but this one is designed to be worn all day along with an electronic monitor (think of a slightly large cell phone) that you can clip to your belt or wear over your shoulder.

The monitor inflates the cuff and checks your blood pressure about every 30 minutes while you are awake and about every 45-60 minutes while you sleep. You need all of this information in order to really understand your blood pressure.

After 20-24 hours you can take the monitor off and return it to the clinic where we will download the information into a report where it will be read by one of our providers.

This monitor will help us decide what type of hypertensive medications or supplements (if any) you may need, how much to use, and when to take them.

Why do we need 24-hour Ambulatory Blood Pressure Monitoring (ABPM)?

Mark Houston, MD, founder of the Hypertension Institute in Nashville, says “if you don’t do a 24-hour ambulatory blood pressure monitor you are approaching medical malpractice.” He goes on to say that you can’t know what drug to use, how much to give, or when to give it without a 24-hour ABPM.”

Virtually everyone should have a 24-hour ambulatory blood pressure monitor at least once!

ABPM is the recommended screening of Hypertension in the UK. It is superior to office and home blood pressure monitoring to predict future cardiovascular events, morbidity, mortality, and target organ damage.

Ambulatory Blood Pressure Monitoring (ABPM) is more accurate than blood pressures obtained in the doctor’s office. ABPM is more predictive of risk for cardiovascular disease events (heart attacks and strokes).

24-hour ambulatory blood pressure monitoring (ABPM) determines ‘dipping status’, white coat hypertension, masked hypertension, circadian rhythm with early morning blood pressure surges, and adequacy of blood control. Ambulatory Blood Pressure Monitoring (ABPM) is cost effective and reduces the number of patients needing drug therapy for hypertension by 25%.1-3, 13

I’ve seen multiple patients who appeared to have hypertension in the office who turned out to have white-coat hypertension and didn’t need blood pressure medications. However, there is also a condition called “masked hypertension” where blood pressure is normal in the doctor’s office but elevated everywhere else.

We simply can’t rely on office BP measurements.4 For years, the standard method for measuring blood pressure has been manual blood pressure monitoring in the doctor’s office. However, manual blood pressure measurements are relatively inaccurate, over-diagnose hypertension by provoking office-induced increases in BP, and correlates poorly with both the awake ambulatory BP and target organ damage. Automated office Blood Pressure (AOBP) is another option for evaluating blood pressure.7

The CAMBO trial showed that automated office blood pressure is better than manual office blood pressure for evaluating and identifying masked hypertension.8

In 2011, the UK National Clinical Guideline Centre (NCGC) guidelines for the management and treatment of hypertension recommended routine use of ambulatory blood pressure monitoring. These guidelines recommended that clinicians “offer ABPM to confirm the diagnosis of hypertension.” In some cases, they recommended waiting for the ABPM results before initiating anti-hypertensive therapy.11

“Compared with making the diagnosis with clinic or home BP monitoring, not only was ABPM determined to be the most cost‐effective approach in all age and sex subgroups, it also led to an improvement in quality health outcomes and was cost‐saving when long‐term costs were taken into account.”11 They went on to say “PCPs should be encouraged to either purchase an ABPM device or seek out specialists who have a device available for use.”11

Good luck trying to find it though.

When I left the military and moved back to Oklahoma I called the cardiology clinic in my group and asked them about ambulatory blood pressure monitoring. They didn’t do it and didn’t know who did. I haven’t been able to find anyone in Oklahoma that does it except us.

What does 24-hour Ambulatory Blood Pressure Monitoring (ABPM) identify?

• Identify white-coat hypertension
• Identify masked hypertension
• Identify normal 24-hour blood pressure patterns (dipping, daytime/nocturnal hypertension)
• Assess hypertension treatment
• Assessing hypertension in the elderly, children/adolescents, pregnancy, high-risk patients
• Identify ambulatory hypotension
• Identify blood pressure patterns in Parkinson’s Disease
• Endocrine hypertension

European Society of Hypertension Position Paper on ABPM

The European Society of Hypertension position paper on ambulatory blood pressure monitoring gives a very nice overview of the scientific evidence for ABPM. The position paper reviews the history, pros and cons of ABPM, cost-effectiveness, appropriate use, how to select an ABPM device, how to implement the device into practice, indications for testing, and interpretation.9

Dipping Blood Pressure

The difference between daytime blood pressure and night time blood pressure is known as blood pressure “dipping.” A normal decrease in blood pressure (dip) is 10-20%. The phenomenon of dipping was first described in 1988 in the Lancet.14

Non-dipping

If your blood pressure doesn’t dip at least 10% then you are considered a “non-dipper” and this is predictive of a future adverse cardiovascular event (such as a heart attack).15

Why non-dipping occurs

At night, you should have decreased sympathetic nervous system (SNS) tone which should decrease blood pressure. If you have increased SNS tone and elevated Angiotensin II then you won’t have sufficient dipping (less than 10%). The non-dipping allows for sodium excretion in the kidney.

Non-dipping is correlated with12 :

• cardiovascular disease
• stroke
• left-ventricular hypertrophy
• congestive heart failure
• increased CIMT
• multifocal leukoencephalopathy
• white matter disease
• silent cerebral infarctions

Risk for ischemic stroke increases if there is excessive dipping (more than 20%).12

Blood pressure load

Another advantage of 24-hour ambulatory blood pressure monitoring (ABPM) is its ability to measure the Blood Pressure Load.

The blood pressure load is the percentage of blood pressure measurements over 140/90. It should be less than 15% for normal. Anything about 15% would be considered abnormal or elevated.

BP load is associated with cardiovascular target organ damage but not independently of the 24 hour blood pressure level. However, more prospective studies with more severe hypertension and those with target organ damage but be done to verify.5,6

Definitions:

• Percentage of blood pressure readings over 140/90. Over 15% is abnormal.
• Percentage of daytime blood pressure readings over 135/85
• A daytime systolic blood pressure over 135 for over 24.5% of readings
• Percentage of night time blood pressure readings over 120/70

References:

1. Bloch, M. J. and Basile, J. N. (2011), UK Guidelines Call for Routine 24‐Hour Ambulatory Blood Pressure Monitoring in All Patients to Make the Diagnosis of Hypertension—Not Ready for Prime Time in the United States. The Journal of Clinical Hypertension, 13: 871-872. doi:10.1111/j.1751-7176.2011.00551.x

2. Liu, Ming; Li, Yan; Wei, Fang-Fei; Zhang, Lu; Han, Jing-Ling; Wang, Ji-Guang. Is blood pressure load associated, independently of blood pressure level, with target organ damage? Journal of Hypertension 2013;31:1812-1818. doi: 10.1097/HJH.0b013e3283624f9b.

3. Alpert BS, Quinn D, Gallick D. Oscillometric blood pressure: a review for clinicians. J Am Soc Hypertens. 2014 Dec;8(12):930-8. doi: 10.1016/j.jash.2014.08.014.

4. Sebo P, Pechère-Bertschi A, Herrmann F, Haller D, Bovier P. Blood pressure measurements are unreliable to diagnose hypertension in primary care. J of Hypertension: March 2014 – Volume 32 – Issue 3 – p 509–517

5. Liu M, Li Y, Wei FF, Zhang L, Han JL, Wang JG. Is blood pressure load associated, independently of blood pressure level, with target organ damage? J Hypertens. 2013 Sep;31(9):1812-8. doi: 10.1097/HJH.0b013e3283624f9b.

6. Rockwood K, Rockwood MR, Mitnitski A. Physiological redundancy in older adults in relation to the change with age in the slope of a frailty index. J Am Geriatr Soc. 2010 Feb;58(2):318-23. doi: 10.1111/j.1532-5415.2009.02667.x.

7. Myers M. The great myth of office blood pressure measurement. J Hypertens. 2012 Oct;30(10):1894-8.

8. Myers MG, Godwin M, Dawes M, Kiss A, Tobe SW, Kaczorowski J. The conventional versus automated measurement of blood pressure in the office (CAMBO) trial: masked hypertension sub-study. J Hypertens. 2012 Oct;30(10):1937-41.

9. O’Brien E, Parati G, Stergiou G, Asmar R, Beilin L, Bilo G, Clement D, de la Sierra A, de Leeuw P, Dolan E, Fagard R, Graves J, Head GA, Imai Y, Kario K, Lurbe E, Mallion JM, Mancia G, Mengden T, Myers M, Ogedegbe G, Ohkubo T, Omboni S, Palatini P, Redon J, Ruilope LM, Shennan A, Staessen JA, vanMontfrans G, Verdecchia P, Waeber B, Wang J, Zanchetti A, Zhang Y. European Society of Hypertension position paper on ambulatory blood pressure monitoring. J Hypertens. 2013 Sep;31(9):1731-68. doi: 10.1097/HJH.0b013e328363e964.

10. Michael A. Weber M, Schiffrin E, White W, Mann S, Lindholm L, Kenerson J, Flack J, Carter B. Clinical Practice Guidelines for the Management of Hypertension in the Community. J of Clinical Hypertension 2013;15:681

11. Bloch M, Basile J. UK Guidelines Call for Routine 24‐Hour Ambulatory Blood Pressure Monitoring in All Patients to Make the Diagnosis of Hypertension—Not Ready for Prime Time in the United States. J of Clinical Hypertension 2011;13(12):871

12. Bloomfield D, Park A. Night time blood pressure dip. World J Cardiol. 2015 Jul 26; 7(7): 373–376.

13. Koroboki E, Manios E, Psaltopoulou T, Vemmos K, Michas F, Alexaki E, Zakopoulos N. Circadian variation of blood pressure and heart rate in normotensives, white-coat, masked, treated and untreated hypertensives. Hellenic J Cardiol. 2012;53:432–438.

14. O’Brien E, Sheridan J, O’Malley K. Dippers and non-dippers. Lancet. 1988;2:397.

15. Mousa T, el-Sayed MA, Motawea AK, Salama MA, Elhendy A. Association of blunted nighttime blood pressure dipping with coronary artery stenosis in men. Am J Hypertens. 2004;17:977–980.

16. Bellelli G, Frisoni GB, Lucchi E, Guerini F, Geroldi C, Magnifico F, Bianchetti A, Trabucchi M. Blunted reduction in night-time blood pressure is associated with cognitive deterioration in subjects with long-standing hypertension. Blood Press Monit. 2004;9:71–76.

17. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL, Jones DW, Materson BJ, Oparil S, Wright JT, et al. Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension. 2003;42:1206–1252.

18. Hermida RC, Moya A, Crespo JJ, Otero A, Dominguez M, Rios MT, Castineira C, Mojon A, Fernandez JR, Ayala DE. Asleep blood pressure is an independent predictor of cardiovascular events: the Hygia project. J Heart Disease. 2014;11:36.