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Updated: Sep 26, 2026
Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound
Published on: December 2, 2014
Peripheral blood pressure measurement is as good as applanation tonometry at predicting ascending aortic blood
Justine I Davies1, Margaret M Band, Stuart Pringle
1Department of Clinical Pharmacology, Department of Cardiology and Department of Epidemiology and Public Health, Ninewells Hospital and Medical School, Dundee DD1 9SY, Scotland, UK. j.i.davies@dundee.ac.uk
Background:
The Sphygmocor system purports to be able to assess ascending aortic blood pressure using a transfer function. It has been shown to be accurate when data obtained invasively are used, but has not been tested prospectively using data obtained non-invasively.
Objective:
To investigate the accuracy of this equipment when measurements are obtained non-invasively, as would normally be the case in the clinic setting.
Design And Methods:
The study was observational. Ascending aortic pressure measurements were taken simultaneously with radial artery pressure wave recordings for estimation of ascending aortic blood pressure, in 28 patients undergoing diagnostic cardiac catheterization.
Results:
The transfer function in the Sphygmocor system significantly underestimated invasively measured systolic blood pressure [mean -7.23 +/- 10.07 mmHg; 95% confidence interval (CI) -3.3 to -11.14 mmHg, P = 0.001] and significantly overestimated invasively measured diastolic blood pressure (mean 12.20 +/- 7.14 mmHg; 95% CI 9.43 to 14.97 mmHg, P <0.001). Oscillometrically measured brachial systolic blood pressure was not significantly different from that measured invasively in the ascending aorta (mean 3.36 +/- 10.47 mmHg; 95% CI -0.69 to 7.43 mmHg, P = 0.1), but oscillometric measurement of brachial diastolic blood pressure gave a significant overestimation of that measured invasively (mean 11.70 +/- 7.18 mmHg; 95% CI 8.91 to 14.49 mmHg, P <0.001). CONCLUSIONS The transfer function in the Sphygmocor system is no better at estimating ascending aortic blood pressure than are standard peripheral blood pressure measurements. It may be necessary to derive a new transfer system that is based on data that are acquired entirely non-invasively.
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This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
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Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
01:10Pre-Procedural Guidelines for Assessing Blood Pressure