Background and objectives: New devices including radial applanation tonometer have been developed for central blood pressure measurement. The devices can noninvasively calculate the central blood pressure. To investigate the accuracy of estimated central blood pressure, this study demonstrates the comparison of catheter based central blood pressure and radial applatnation tonometer based central blood pressure.
Materials and Methods: Seventy two patients (64 ± 10 years old) underwent cardiac catheterization were recruited for this study. Ascending aortic pressure was measured using a pressure guide wire (RADI Medical Systems), and recorded on a laptop personal computer through a SEIREG polygraph (Siemens). Radial arterial pulse waves were simultaneously measured noninvasively using applanation tonometry technique by HEM-9000AI (Omron Healthcare Co.,Ltd.) and SphygmoCor (AtCor Medical Pty Ltd.). The measurements were performed before and after administration of vasodilator (nicorandil or glycerol trinitrate) or antihypertensive (nicardipine hydrochloride) drugs. The central blood pressure calculated by HEM-9000AI (cSBP) and SphygmoCor (aSBP Sphy) was compared respectively with that by catheter (aSBP).
Results: cSBP and aSBP Sphy indicated significant correlation with aSBP (r=0.94, 0.93, respectively, p=0.001). The regression line slope of cSBP to aSBP was 0.92 and that of aSBP Sphy to aSBP was 0.76. A significant difference was observed between aSBP and aSBP Sphy, but was not observed between aSBP and cSBP. Bland-Altman test showed that the difference of cSBP to aSBP was - 0.4 ± 9.6 mmHg and that of aSBP Sphy to aSBP was -9.0 ± 10.3 mmHg. It shows significant difference between cSBP to aSBP error and aSBP Sphy to aSBP error (p<0.05).
Conclusion: The central blood pressure measured by HEM-9000AI is very close to that by catheter. These findings indicate that noninvasive central blood pressure measurement by radial applanation tonometry is accurate enough for clinical applications.
A New Approach to Validate the Use of Brachial Blood Pressure to Assess Non-Invasive Aortic Pressure in Human Beings
