Ambulatory blood pressure
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Ambulatory blood pressure monitoring (ABPM) measures blood pressure at regular intervals throughout the day and night. It is believed to be able to reduce the white coat hypertension effect in which a patient's blood pressure is elevated during the examination process due to nervousness and anxiety caused by being in a clinical setting. Out-of-office measurements are highly recommended as an adjunct to office measurements by almost all hypertension organizations.[1].
Nocturnal Hypertension
Ambulatory blood pressure monitoring allows blood pressure to be continually monitored during sleep, and is useful to determine whether the patient is a dipper or non-dipper, that is to say whether or not blood pressure falls at night compared to daytime values. A night time fall is normal. It correlates with relationship depth but other factors such as sleep quality, age, hypertensive status, marital status, and social network support.[2] Absence of a night time dip is associated with poorer health outcomes, including increased mortality in one recent study.[3] In addition, nocturnal hypertension is associated with end organ damage[4] and is a much better indicator than the daytime blood pressure reading.
Target Organ Damage
Template:Seealso It has been shown that end-organ damages related to hypertension, such as left ventricular hypertrophy, narrowing of the retinal arteries are more strongly associated with ABPM than with a clinical BP measurement, the reason being clinical BP measurement are referred to the marked variability of BP measurement and white coat effect [5][6][7][8][9].
Morning Surge
Optimal blood pressure fluctuates over a 24-hour sleep-wake cycle, with values rising in the daytime and falling after midnight. The reduction in early morning blood pressure compared with average daytime pressure is referred to as the night-time dip. Ambulatory blood pressure monitoring may reveal a blunted or abolished overnight dip in blood pressure. This is clinically useful information because non-dipping blood pressure is associated with a higher risk of left ventricle hypertrophy and cardiovascular mortality. By comparing the early morning pressures with average daytime pressures, a ratio can be calculated which is of value in assessing relative risk. Dipping patterns are classified by the percent of drop in pressure, and based on the resulting ratios a person may be clinically classified for treatment as a "non-dipper" (with a blood pressure drop of less than 10%), a "dipper," an "extreme dipper," or a "reverse dipper," as detailed in the chart below. Additionally, ambulatory monitoring may reveal an excessive morning blood pressure surge; which is associated with increased risk of stroke in elderly people with high blood pressure.[10][11]
Classification of dipping in blood pressure is based on the American Heart Association's calculation, using systolic blood pressure (SBP) as follows:
- Dip = (1 - {SBRsleeping/SBPwaking}) * 100%
| Range | Class |
|---|---|
| <0% | Reverse Dipper |
| 0% - 10% | Non-Dipper |
| 10% - 20% | Dipper |
| >20% | Extreme Dipper |
Blood Pressure Variability
24-hour, non-invasive ambulatory blood pressure monitoring allows estimates of BP variability.
References
- ↑ Verdecchia P, Angeli F, Gattobigio R (2004). "Clinical usefulness of ambulatory blood pressure monitoring". J. Am. Soc. Nephrol. 15 Suppl 1: S30–3. PMID 14684668. Unknown parameter
|month=ignored (help) - ↑ Holt-Lunstad J, Jones BQ, Birmingham W. (2009).The influence of close relationships on nocturnal blood pressure dipping. Int J Psychophysiol. 71(3):211-7. doi:10.1016/j.ijpsycho.2008.09.008 PMID 18930771
- ↑ Minutolo R, Agarwal R, Borrelli S, Chiodini P, et al (2011). Prognostic role of ambulatory blood pressure measurement in patients with nondialysis chronic kidney disease. Arch Intern Med. 171(12):1090-8.
- ↑ Use and interpretation of ambulatory blood pressure monitoring: recommendations of the British Hypertension Society
- ↑ Clinical Usefulnesses of Ambulatory Blood Pressure Monitoring, Paolo Verdecchia, Fabio Angeli, Roberto Gattobigio
- ↑ Doménech M, Berruezo A, Molina I, Mont L, Coca A (2013). "Nighttime Ambulatory Blood Pressure is Associated With Atrial Remodelling and Neurohormonal Activation in Patients With Idiopathic Atrial Fibrillation". Rev Esp Cardiol. doi:10.1016/j.recesp.2012.11.011. PMID 23427898. Unknown parameter
|month=ignored (help) - ↑ Silva-Néto RP, Bernardino SN (2013). "Ambulatory Blood Pressure Monitoring in Patient With Hypnic Headache: A Case Study". Headache. doi:10.1111/head.12066. PMID 23425041. Unknown parameter
|month=ignored (help) - ↑ Krakoff LR (2013). "Ambulatory blood pressure improves prediction of cardiovascular risk: implications for better antihypertensive management". Curr Atheroscler Rep. 15 (4): 317. doi:10.1007/s11883-013-0317-9. PMID 23423525. Unknown parameter
|month=ignored (help) - ↑ Luo Y, Wang YL, Wu YB; et al. (2013). "Association between the rate of the morning surge in blood pressure and cardiovascular events and stroke". Chin. Med. J. 126 (3): 510–4. PMID 23422116. Unknown parameter
|month=ignored (help) - ↑ Morning surge in blood pressure linked to strokes in elderly
- ↑ Stroke Prognosis and Abnormal Nocturnal Blood Pressure Falls in Older Hypertensives