3.4 RESERVOIR PRESSURE SEPARATION AT BRACHIAL, CAROTID AND RADIAL ARTERIES: A QUANTITATIVE COMPARISON AND EVALUATION

Michael Ebner; Kim Parker; Tom Vercauteren; Sébastien Ourselin; Siegfried Wassertheurer; Alun Hughes; Bernhard Hametner

doi:10.1016/j.artres.2017.10.034

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Volume 20, Issue C, December 2017, Pages 54 - 54

3.4 RESERVOIR PRESSURE SEPARATION AT BRACHIAL, CAROTID AND RADIAL ARTERIES: A QUANTITATIVE COMPARISON AND EVALUATION

Authors

Michael Ebner¹, Kim Parker², Tom Vercauteren³^{, 1}, Sébastien Ourselin³^{, 1}, Siegfried Wassertheurer⁴, Alun Hughes⁵, Bernhard Hametner⁴

¹Translational Imaging Group, Centre for Medical Image Computing, Department of Medical Physics and Biomedical Engineering, University College London, London, UK

²Department of Bioengineering, Imperial College London, London, UK

³Wellcome/EPSRC Centre for Interventional and Surgical Sciences, University College London, London, UK

⁴Center for Health & Bioresources, AIT Austrian Institute of Technology, Vienna, Austria

⁵Institute of Cardiovascular Science, University College London, London, UK

Available Online 6 December 2017.

DOI

10.1016/j.artres.2017.10.034 How to use a DOI?

Abstract

Background: At present, reservoir pressure parameters are derived from arterial pressure waveforms regardless of the location of measurement. However, a comparison between sites has not been made, and site-related differences may affect interpretation. In this study, we computed reservoir pressure waveform separations on hypertensive individuals where brachial, carotid and radial pressure measurements were available and quantitatively assessed their results.

Methods: 95 participants in the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) had sequential measurements of pressure and flow velocity waveforms from carotid, brachial and radial arteries [1]. Pre-processing was performed to impose identical diastolic and mean blood pressures at all three arterial locations. Using pressure information only, reservoir pressure separation was performed [2, 3]. Systolic durations were estimated based on minimum pressure waveform derivatives.

Reservoir curves characterized by physiologically implausible parameters, i.e. a rate constant b < 0 or an asymptotic pressure P∞ < 0, were discarded, leaving 74 subjects with valid reservoir pressure waveforms at all three arterial locations.

Results: Estimated reservoir parameters are shown in Table 1. We observed significant differences between arteries in almost all parameters. A high correlation was observed between reservoir pulse pressure and reservoir pressure area at all locations, and the correlation between brachial and radial arteries was stronger for all parameter.

Reservoir	Brachial Artery(B)	Carotid Artery(C)	Radial Artery(R)	r(B,C)	r(B,R)	r(C,R)
PP [mmHg]	37.1 ± 8.6	41.6 ± 9.0	36.1 ± 8.4	0.84^*	0.95^*	0.84^*
A_p [mmHg s]	16.7 ± 5.0	19.0 ± 4.4	16.0 ± 4.3	0.91^*	0.96^*	0.91^*
P_∞ [mmHg]	61.6 ± 14.2	66.6 ± 12.8	66.2 ± 11.2	0.50^*	0.51^*	0.46^*
A [1/s]	8.3 ± 3.7	11.4 ± 2.7	7.0 ± 2.7	0.11^*	0.91^*	0.18^*
B [1/s]	1.8 ± 0.6	2.2 ± 0.9	2.1 ± z0.7	0.30^*	0.62^*	0.40^*

Table 1

Quantification of reservoir pressures at three arterial locations in the format of mean ± standard deviation based on 74 subjects whereby PP denotes the reservoir pulse pressure, A_p the area of reservoir pressure above diastolic blood pressure, P_∞ the asymptotic blood pressure and a, b = 1/τ the rate constants with the time constant τ describing the diastolic pressure decay. The correlation coefficient r is computer between relevant arterial locations. The statistical significance of the differences between locations was based on a paired t-test with * indicating p < 0.05.

Conclusions: The results of this study indicate differences in parameters derived from reservoir pressure separation at different arterial locations. This suggests that interpretations cannot be made agnostic to the location of measurement.

Open Access

This is an open access article distributed under the CC BY-NC license.

References

1.CH Manisty, A Zambanini, KH Parker, JE Davies, DP Francis, J Mayet, SA McG Thom, and AD Hughes, “Differences in the magnitude of wave reflection account for differential effects of amlodipine- versus atenolol-based regimens on central blood pressure: an Anglo-Scandinavian Cardiac Outcome Trial substudy,”, Hypertension, Vol. 54, No. 4, Oct 2009, pp. 724-30.

2.J Aguado-Sierra, J Alastruey, J-J Wang, N Hadjiloizou, J Davies, and KH Parker, “Separation of the reservoir and wave pressure and velocity from measurements at an arbitrary location in arteries,”, Proc Inst Mech Eng Part H J Eng Med, Vol. 222, No. 4, 2008, pp. 403-416.

3.JE Davies, P Lacy, T Tillin, D Collier, JK Cruickshank, DP Francis, A Malaweera, J Mayet, A Stanton, B Williams, KH Parker, SA McG Thom, and AD Hughes, “Excess pressure integral predicts cardiovascular events independent of other risk factors in the conduit artery functional evaluation substudy of Anglo-Scandinavian Cardiac Outcomes Trial,”, Hypertension, Vol. 64, No. 1, Jul 2014, pp. 60-8.

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Journal: Artery Research
Volume-Issue: 20 - C
Pages: 54 - 54
Publication Date: 2017/12/06
ISSN (Online): 1876-4401
ISSN (Print): 1872-9312
DOI: 10.1016/j.artres.2017.10.034 How to use a DOI?
Open Access: This is an open access article distributed under the CC BY-NC license.

Cite this article

ris enw bib

TY  - JOUR
AU  - Michael Ebner
AU  - Kim Parker
AU  - Tom Vercauteren
AU  - Sébastien Ourselin
AU  - Siegfried Wassertheurer
AU  - Alun Hughes
AU  - Bernhard Hametner
PY  - 2017
DA  - 2017/12/06
TI  - 3.4 RESERVOIR PRESSURE SEPARATION AT BRACHIAL, CAROTID AND RADIAL ARTERIES: A QUANTITATIVE COMPARISON AND EVALUATION
JO  - Artery Research
SP  - 54
EP  - 54
VL  - 20
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2017.10.034
DO  - 10.1016/j.artres.2017.10.034
ID  - Ebner2017
ER  -

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