P6.19 PHYSIOLOGICAL CORRELATES OF AORTIC RESERVOIR AND EXCESS PRESSURE IN MAN

DOI

10.1016/j.artres.2013.10.200How to use a DOI?

Abstract

Background: Central (aortic) blood pressure (BP) indices independently predict cardiovascular events and all-cause mortality, but the physiological mechanisms underlying aortic BP waveform morphology are subject to debate. The ‘aortic reservoir’ and ‘excess pressure’ are proposed as determinants of aortic BP, but this relationship has only been assessed using a mathematically-derived aortic reservoir-excess pressure model (AR_derived and XP_derived). This study aimed to directly measure the aortic reservoir (AR_direct; by cyclic change in aortic volume) and determine the relationship with AR_derived and aortic BP.

Methods: Ascending aortic BP and Doppler flow velocity were recorded via intra-arterial wire in 10 males (aged 62±12 years) during coronary artery bypass graft surgery. Simultaneous ascending aortic transesophageal echocardiography was used to measure AR_direct. Published mathematical formulae were used to determine AR_derived and XP_derived. A direct excess pressure (XP_direct) was calculated by subtracting AR_direct from aortic BP.

Results: When normalised to the same scale (Figure A), AR_direct (solid line) was strongly and linearly related to AR_derived (broken line) during systole (r=0.980, P<0.001, Figure B, point 1–2) and diastole (r=0.987, P<0.001 Figure B, point 2–3). The cyclic relationship between aortic BP and AR_direct was qualitatively and quantitatively (P>0.05) similar to the cyclic relationship between aortic BP and AR_derived. Furthermore, XP_direct was linearly related to XP_derived during systole (r=0.909, P<0.001) and diastole (r=0.663, P<0.001).

Conclusion: Aortic reservoir and excess pressures are physiological phenomena highly related to mathematically-derived aortic reservoir, excess pressure and aortic BP.

Open Access

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

TY  - JOUR
AU  - M.G. Schultz
AU  - J.E. Davies
AU  - A. Hardikar
AU  - S. Pitt
AU  - A.D. Hughes
AU  - J.E. Sharman
PY  - 2013
DA  - 2013/11/11
TI  - P6.19 PHYSIOLOGICAL CORRELATES OF AORTIC RESERVOIR AND EXCESS PRESSURE IN MAN
JO  - Artery Research
SP  - 159
EP  - 159
VL  - 7
IS  - 3-4
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2013.10.200
DO  - 10.1016/j.artres.2013.10.200
ID  - Schultz2013
ER  -