Ambulatory Blood Pressure Monitoring Guidelines

Device Selection

The American College of Cardiology recommends using validated oscillometric devices that meet AAMI or BHS standards for ambulatory blood pressure monitoring (ABPM), with a preference for devices providing comprehensive 24-hour data and minimal patient discomfort 1
Devices should measure every 15-30 minutes over a 24-hour period, store 50-100 readings, and have a memory function to prevent data fabrication, with proper cuff sizing (approximately 40% of mid-arm circumference) 1, 2
A comprehensive list of validated monitors is available at www.dableducational.org, which can be used to select devices meeting AAMI or BHS standards 1

Normal ABPM values are defined as daytime: <135/85 mmHg, nighttime: <120/70 mmHg, and 24-hour: <130/80 mmHg, according to the American Heart Association 2
Abnormal ABPM values are defined as daytime: >140/90 mmHg, nighttime: >125/75 mmHg, and 24-hour: >135/85 mmHg, according to the American Heart Association 2

Oscillometric technology calculates systolic, diastolic, and mean arterial pressure (MAP) through proprietary algorithms analyzing arterial wall oscillations detected during cuff deflation, with MAP directly determined at the point of maximum oscillation amplitude 2
Systolic and diastolic pressures are estimated using manufacturer-specific algorithms, rather than being directly measured, which can lead to differences in readings between devices 2, 3
The auscultatory method uses Korotkoff sounds detected by stethoscope, with systolic pressure recorded at first sound (phase 1) and diastolic pressure recorded at disappearance of sounds (phase 5), as recommended by the European Heart Journal 4, 5
Ultrasound techniques use Doppler shift to detect arterial wall movement, and are particularly useful in patients with faint Korotkoff sounds, according to Circulation and Hypertension 2, 3
The finger cuff method (Penaz method) uses photoplethysmography to detect arterial pulsation, but is more suitable for research than clinical use, as stated in Circulation and Hypertension 2, 3

Inaccurate readings can occur due to failure to maintain arm at heart level, improper cuff sizing, and patient positioning, which can be mitigated by proper patient education and technique 6, 5
Misinterpretation of data can occur due to incorrect day/night divisions, reliance on automated filters, and failure to account for activity levels during monitoring, which can be mitigated by careful review of the data and consideration of individual patient factors 1
Most oscillometric devices are not validated for use in atrial fibrillation and may provide inaccurate readings in these patients, according to the European Heart Journal 4, 5
Using inappropriately sized cuffs, taking measurements through clothing, and failure to allow adequate rest time before measurement can significantly affect accuracy, according to Praxis Medical Insights 5