Accuracy of oscillometric blood pressure measurement in atrial fibrillation

OBJECTIVE: The primary aim of this study was to assess the accuracy of automated oscillometry (AO) in outpatients with atrial fibrillation (AF). The secondary aim was to explore whether AO accuracy is influenced by beat-to-beat blood pressure (BP) variability or heart frequency (HF).

METHODS: Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by AO and beat-to-beat BP using a validated Volume Clamp Method (VCM) technique. AO accuracy was analyzed separately in tertiles of beat-to-beat BP variability and HF.

RESULTS: The main study included 58 AF and 38 sinus rhythm (SR) patients in whom the Welch Allyn Spot Vital Signs (WASVS) was used. An auxiliary study in 23 AF patients used the Philips M3002A IntelliVue ×2. For AF and SR patients, respectively, SBP by WASVS deviated by +0.1 (±14.8) mmHg and -7.9 (±15.7) mmHg from VCM. WASVS-DBP was higher than VCM in AF and SR by 6.3 (±9.2) mmHg and 5.0 (±7.7) mmHg, respectively. High beat-to-beat BP variability and high HF decreased WASVS accuracy for both SBP and DBP. SBP and DBP measurements by Philips M3002A IntelliVue ×2 deviated by -6.8 (±13.2) mmHg and 9.4 (±8.1) mmHg, respectively.

CONCLUSION: Overall, AO accuracy in AF is limited; in individual patients, AO inaccuracy may be considerable. AO accuracy is especially reduced in patients showing large beat-to-beat BP variability or high HF.