Artery Research

Volume 25, Issue Supplement 1, December 2019, Pages S103 - S104

P62 Estimation of Wave Intensity in Humans Using only Pressure Waveforms and Reservoir Analysis

Authors
Alun Hughes1, 2, *, Kim Parker3, Nish Chaturvedi1, 2, Chloe Park1
1Department of Population Science & Experimental Medicine, Institute of Cardiovascular Science, UCL, London, UK
2MRC Unit for Lifelong Health and Aging@UCL, London, UK
3Department of Bioengineering, Imperial College London, UK
*Corresponding author. Email: alun.hughes@ucl.ac.uk
Corresponding Author
Alun Hughes
Available Online 17 February 2020.
DOI
10.2991/artres.k.191224.093How to use a DOI?
Abstract

Background: Measurement of wave intensity (WI) requires simultaneous or quasi-simultaneous measurement of pressure and flow limiting its use. Previous work in dogs [1] and humans [2] has shown that the excess pressure waveforms calculated using reservoir analysis correspond closely with aortic flow waveforms. This offers a potential method to estimate WI using only pressure waveforms (pWI). We investigated the feasibility of this approach and agreement with established methods.

Methods: 262 participants (68.3 (SD = 5.5); 74% male) without aortic stenosis or heart failure were recruited from a UK-based longitudinal study, Southall and Brent Revisited. Central pressure waveforms, aortic flow velocity and carotid WI were measured using tonometry (Sphygmocor, AtCor), echocardiography (iE33, Philips) and ultrasonography (SSD-5500, Aloka) respectively. Reservoir analysis was performed as previously described [2] and excess pressure waveforms were calibrated to flow velocity assuming a peak velocity of 1 m/s. Method agreement was assessed as mean difference (MD), limits of agreement (LOA) and concordance coefficient (CC).

Results: Analysis failed in 9 individuals; results for those with analysable data are shown in Table 1. Aortic pWI was higher than aortic WI but showed good concordance (logW1: MD(LOA) = −0.41(−0.73, −0.09) CC = 0.7; logW2: MD(LOA) = −0.41 (−0.73, −0.09); CC = 0.7). Agreement of pWI with carotid WI showed no bias and concordance was fair to poor (logW1: MD (LOA) = −0.16 (−1.30, 0.99) CC = 0.3; logW2: MD (LOA) = −0.02 (−1.23, 1.2); CC = 0.1).

Variables N Median/(%) p25 p75
Age, y 207 67.9 63.6 71.9
BMI, kg/m2 207 26.6 24.1 30.1
Systolic BP, mmHg 207 139 126 148
Diastolic BP, mmHg 207 76 70 82
Heart rate, bpm 207 66 59 74.5
Male sex, % 150 72.5
Ethnicity
  European 88 (42.5%)
  South Asian 75 (36.2%)
  African Caribbean 44 (21.3%)
Current smoker 18 (8.8%)
Diabetes 65 (31.4%)
Hypertension 130 (62.8%)
Aorta
  W1, mmHg.m.s−3 207 7103 5041 9910
  W2, mmHg.m.s−3 207 1637 1147 2518
  pW1, mmHg.m.s−3 207 10,526 7677 14,336
  pW2, mmHg.m.s−3 207 2491 1779 3560
  time W1 to W2, s 207 0.25 0.23 0.27
  Peak velocity, m/s 207 1.34 1.2 1.46
Carotid artery
  W1, mmHg.m.s-3 207 8714 6550 12,883
  W2, mmHg.m.s-3 207 2327 1471 3227
  time W1 to W2, s 207 0.29 0.27 0.31
  Peak velocity, m/s 207 1.10 0.92 1.30

BMI, body mass index; BP, blood pressure; p25, 25th centile; p75, 75th centile; pW1, peak intensity of initial forward compression wave (W1) estimated using pressure only; pW2, peak intensity of initial forward compression wave (W2) estimated using pressure only; W1, peak intensity of initial forward compression wave (W1) calculated using aortic velocity; W2, peak intensity of initial forward compression wave (W2) calculated using aortic velocity.

Table 1

Results

Conclusion: Estimation of aortic WI from pressure waveforms using reservoir analysis is feasible.

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/).

References

[1]Wang et al., Am J Physiol Heart Circ Physiol, Vol. 284, 2003, pp. H1358-H68.
[2]Michail et al., Physiol Meas, Vol. 39, 2018. 064006.
Journal
Artery Research
Volume-Issue
25 - Supplement 1
Pages
S103 - S104
Publication Date
2020/02/17
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.2991/artres.k.191224.093How to use a DOI?
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/).

Cite this article

TY  - JOUR
AU  - Alun Hughes
AU  - Kim Parker
AU  - Nish Chaturvedi
AU  - Chloe Park
PY  - 2020
DA  - 2020/02/17
TI  - P62 Estimation of Wave Intensity in Humans Using only Pressure Waveforms and Reservoir Analysis
JO  - Artery Research
SP  - S103
EP  - S104
VL  - 25
IS  - Supplement 1
SN  - 1876-4401
UR  - https://doi.org/10.2991/artres.k.191224.093
DO  - 10.2991/artres.k.191224.093
ID  - Hughes2020
ER  -