Measurement of central systolic blood pressure by pulse volume plethysmography with a noninvasive blood pressure monitor.

BACKGROUND

Central systolic blood pressure (SBP) can be estimated by an oscillometric method developed from a pulse volume plethysmography (PVP) device. The present study applied this novel method to a noninvasive blood pressure monitor (NBPM).

METHODS

We enrolled 50 patients (37 men, age range 30-84 years) referred for cardiac catheterization. Invasive right brachial and central aortic pressures (using a dual-sensor pressure catheter), and noninvasive left brachial SBP and diastolic blood pressure (DBP), and PVP waveform (using a customized NBPM) were simultaneously recorded. Central SBP was estimated by analysis of the PVP waveform calibrated to the noninvasive SBP and DBP, using both the original (CSBP-O) and the newly generated (CSBP-N) regression equations. The reproducibility of the invasive central SBP by CSBP-O and CSBP-N was examined using the concordance correlation coefficient.

RESULTS

Overall, the invasive central aortic SBP ranged 86-176 with a mean of 124 ± 21 mm Hg. The mean differences between the estimated and the invasive central SBP were -1.3 ± 6.7 mm Hg for CSBP-O and 0.0 ± 6.2 mm Hg for CSBP-N, respectively. The concordance correlation coefficients for CSBP-O and CSBP-N were 0.94 (95% confidence interval (CI): 0.93-0.94) and 0.95 (95% CI: 0.95-0.96), and both were significantly better than that for the noninvasive brachial SBP (0.87, 0.84-0.91) indicated by non-overlapping CIs.

CONCLUSIONS

The PVP method for noninvasive estimation of central SBP can be applied to a commonly used NBPM. Whether the NBPM-derived central SBP is superior to the noninvasive brachial SBP in the prediction of cardiovascular risks remains to be investigated.