P122 Unrealistic Pulse Pressures from Calibrated Tonometric Waveforms

DOI

10.2991/artres.k.191224.148How to use a DOI?

Abstract

Background: Calibration of carotid artery tonometry waveforms needs to account for pulse pressure augmentation [1]. Due to its location nearer to the heart, carotid pulse pressure (carPP) is about 10 mmHg lower than brachial (brachPP) [1]. In practice, perfect applanation is hard to achieve with tonometry and thus tracking-errors may occur, leading to an exaggerated fall in the diastolic limb of the tonometry waveform. Consequently, the mean-to-diastolic difference of the waveform is underestimated, leading to an overestimation of carPP after calibration. We assessed the relationship between brachPP and carPP in 100 subjects, aged 18–80 yrs.

Methods and Results: Brachial pressure (Omron) and carotid tonometry (Sphygmocor) measurements were performed by a single, highly skilled vascular technician, according to Artery Society methodological standards. CarPP was 5 ± 13 mmHg lower than brachPP. Bland-Altman analysis revealed a positive trend (r = 0.695, p < 0.0001) between the carPP–brachPP difference and their mean, with carPP being 20 mmHg lower than brachPP at a mean 40 mmHg which extended to carPP being 20 mmHg higher(!) than brachPP at a mean 80 mmHg. Accordingly, 30% of the study population showed unphysiological carPP, indicating an unrealistic i.e. reverse amplification. Even with a tolerance of +5 mmHg, still 20% of cases showed unrealistic values.

Conclusion: In practice, calibrated carotid tonometry waveforms may yield unphysiological overestimations of carotid pulse pressure. This finding implies (potential) estimation errors in regression model studies on central pressure and local stiffness, suggesting brachial pulse pressure would be a valid compromise.

Copyright

© 2019 Association for Research into Arterial Structure and Physiology. Publishing services by Atlantis Press International B.V.

Open Access

This is an open access article distributed under the CC BY-NC 4.0 license (http://creativecommons.org/licenses/by-nc/4.0/).

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TY  - JOUR
AU  - Koen Reesink
AU  - Louise Marais
AU  - Pierre Boutouyrie
PY  - 2020
DA  - 2020/02/17
TI  - P122 Unrealistic Pulse Pressures from Calibrated Tonometric Waveforms
JO  - Artery Research
SP  - S162
EP  - S162
VL  - 25
IS  - Supplement 1
SN  - 1876-4401
UR  - https://doi.org/10.2991/artres.k.191224.148
DO  - 10.2991/artres.k.191224.148
ID  - Reesink2020
ER  -