Understanding Less Than 70% Accurate Readings on ABPM

Introduction to ABPM Interpretation

The European Society of Cardiology recommends that at least 70% of blood pressure readings during both daytime and nighttime periods must be satisfactory for the monitoring to be considered interpretable, with typically ≥27 measurements over 24 hours, and preferably seven nocturnal readings obtained 1, 2, 3, 4

Movement artifact is a common cause of failed readings, particularly during arm movement or physical activity 5
Improper cuff positioning, such as cuff slippage or kinks in the tubing, can cause failed readings during normal activities 5
Patient cancellation of readings, using the cancellation button when the cuff inflates at inconvenient times, can lead to failed readings 5
Excessive physical activity, such as vigorous exercise or contact sports, often results in failed readings 6
Irregular cardiac rhythm, such as atrial fibrillation, may produce unreliable readings regardless of proper technique 1, 2

The 2024 ESC guidelines specify that blood pressure values should be below the thresholds of 24-hour ≥130/80 mmHg, daytime ≥135/85 mmHg, and nighttime ≥120/70 mmHg to be considered normal 3, 4
If less than 70% of readings are valid, the study should be repeated to ensure reliable interpretation 1, 2

The European Society of Cardiology recommends reviewing the patient diary to identify specific times when readings failed, and providing enhanced patient education on proper technique, including keeping the arm still and at heart level during cuff inflation, avoiding strenuous exercise, and ensuring proper device positioning 1, 2, 3, 4, 5, 6
Scheduling a repeat ABPM with more frequent measurement intervals, such as every 20 minutes, can increase the likelihood of obtaining ≥70% valid readings 1, 2