Introduction Blood pressure (BP) is routinely measured by the automated sphygmomanometer. Accurate assessment of BP in patients (pts) with atrial fibrillation (AF) is crucial but impossible due to beat-to-beat variability of stroke volume and significant BP fluctuation preventing consistent assessment of Korotkoff sounds. The PulseCor R6.5 (PC) detects arrhythmia and pulse pressure fluctuations, utilising suprasystolic waveform algorithms to estimate central BP and allows assessment of arterial stiffness, a risk factor for AF. We analysed the accuracy of (i) manual sphygmomanometers, (ii) automated sphygmomanometers and (iii) the PC against continuous invasive BP monitoring via inserted radial cannulae (the gold standard).

Methods 10 pts (6 controls in sinus rhythm (SR) and 4 in AF) aged 23–76 (70% male) were identified with arterial lines in situ. Adjustment to atmospheric zero was performed prior to each BP measurement. Non-invasive BP measurements were taken immediately following the invasive BP measurement in a randomised sequence and this was repeated three times in each pt.

Results See Table 1.

The PC is the only accurate non-invasive assessment of systolic BP in AF pts, better than both automated and manual sphygmomanometers (p=0.02 and 0.015, respectively). In SR the manual sphygmomanometer is more accurate assessing systolic BP than the PC and automated sphygmomanometer (p=0.003 and 0.04, respectively).

Conclusions Accurate non-invasive BP assessment in AF is essential and is superior in pts with this arrhythmia using the PC with suprasystolic algorithms but not in SR where the manual sphygmomanometer is best.