Asymmetrical oscillometric pulse waveform envelopes in normotensive and hypertensive subjects

This study investigated the symmetry of the oscillometric waveform shape obtained during noninvasive auscultatory blood pressure measurement. The oscillometric cuff pressures were recorded from ten normotensive and ten hypertensive subjects. The cuff pressure corresponding to the maximum oscillometric pulse was taken as the automated mean arterial pressure (MAP). The cuff pressures corresponding to 30%, 50% and 70% of the maximum oscillometric pulse peak amplitude were measured for both the high and low pressure regions. At the three different thresholds, the cuff pressure widths (absolute difference to the MAP) in the high and low pressure regions were compared. For both the normotensive and hypertensive groups, the cuff pressure widths in the high pressure region were significantly larger than in the low pressure region at the normalised amplitude levels of 50% and 70% (all P<;0.01), which confirmed an asymmetrical feature of the oscillometric waveform envelope.