Artery Research

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Volume 24, Issue C, December 2018, Pages 70 - 71

2.5 DOES WAVE REFLECTION PROTECT THE MICROVASCULATURE FROM HIGH PULSE PRESSURE?

Authors
Avinash Kondiboyina1, 2, Joe Smolich3, 2, Michael Cheung3, 2, 4, Berend Westerhof5, Nico Westerhof5, Jonathan Mynard1, 2, 6
1Murdoch Children’s Research Institute, Parkville, VIC, Australia
2University of Melbourne, Parkville, VIC, Australia
3Murdoch Childrens Research Institute, Parkville, VIC, Australia
4Royal Children’s Hospital, Parkville, VIC, Australia
5VU University Medical Center, Amsterdam, the Netherlands
6Royal Children’s Hospital, Parkville, VIC, Australia
Available Online 4 December 2018.
DOI
10.1016/j.artres.2018.10.028How to use a DOI?
Abstract

Background: Wave reflection (caused by a stiffness increase from large to small arteries) has been considered to protect against high microvasculature Pulse Pressures (mPP) (1). However, according to transmission line theory, Transmission (T) and Reflection (R) coefficients are proportional (T = 1+R), implying that reflection would not be protective. Proximal arterial stiffening with aging is associated with reduced Total Arterial Compliance (TAC) and increased forward Pressure (Pfw). We hypothesized that a high TAC and low Pfw, rather than high R, are responsible for protection from mPP.

Methods: We constructed a fractal arterial tree containing 5008 vessels across 14 generations (fractal exponent 2.76, asymmetry ratio 0.8). Wave speed in each vessel was prescribed to achieve a uniform reflection coefficient (R = -0.025, 0, 0.025 or 0.05) at every junction, achieved by progressively stiffening distal vessels while keeping aortic wave speed constant (“distal-stiffening”) or by progressively stiffening proximal vessels while keeping average wave speed in all terminal vessels constant (“proximal-stiffening”, see Figure. An elastance heart model was applied at the inlet and simulations were performed with a one-dimensional flow solver (2).

Results: Proximal-stiffening and distal-stiffening had opposing effects on R but the same effects on mPP, whereas mPP increased monotonically with decreasing TAC and increasing Pfw in both settings (Figure).

Conclusion: Wave reflection per se does not provide protection from high mPP since greater reflection also entails greater transmitted pressure. Although a decreased R may accompany proximal arterial stiffening, the likely mechanism of increased mPP with aging is decreased TAC and greater Pfw.

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<Previous Article In Issue
Next Article In Issue>
Journal
Artery Research
Volume-Issue
24 - C
Pages
70 - 71
Publication Date
2018/12/04
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.1016/j.artres.2018.10.028How to use a DOI?
Open Access
This is an open access article distributed under the CC BY-NC license.

Cite this article

risenwbib
TY  - JOUR
AU  - Avinash Kondiboyina
AU  - Joe Smolich
AU  - Michael Cheung
AU  - Berend Westerhof
AU  - Nico Westerhof
AU  - Jonathan Mynard
PY  - 2018
DA  - 2018/12/04
TI  - 2.5 DOES WAVE REFLECTION PROTECT THE MICROVASCULATURE FROM HIGH PULSE PRESSURE?
JO  - Artery Research
SP  - 70
EP  - 71
VL  - 24
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2018.10.028
DO  - 10.1016/j.artres.2018.10.028
ID  - Kondiboyina2018
ER  -