Artery Research

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Volume 20, Issue C, December 2017, Pages 83 - 83

P167 PULSE PRESSURE AMPLIFICATION AND AUGMENTATION INDEX CHANGE IN OPPOSITE MANNER WITH ARTERIAL STIFFNESS INDEPENDENTLY OF SYSTEMIC RESISTANCE

Authors
Nicolaas Westerhof1, Berend Westerhof1, 2
1Department of Pulmonary Diseases, VU University Medical Center, Amsterdam, The Netherlands
2Department of Medical Biology, Section Systems Physiology, Laboratory for Clinical Cardiovascular Physiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
Available Online 6 December 2017.
DOI
10.1016/j.artres.2017.10.116How to use a DOI?
Abstract

Background: Pulse Pressure Amplification (PPA) is the increase in Pulse Pressure (PP) from proximal to distal arteries. The Augmentation Index (AIx) is the secondary increase in aortic pressure in systole relative to PP. With aging and increased arterial stiffness the PPA decreases while the AIx increases. Since both depend on the reflection of pressure waves, the finding that PPA and AIx change in opposite ways seems surprising.

Methods: Aortic PPA, AIx and Reflection Magnitude (RM = Preflected/Pforward) were determined in a multibranched model and during control and Valsalva Maneuver in the human.

Results: During the Valsalva Maneuver reflections decrease: the lower mean arterial pressure results in lower stiffness and Pulse Wave Velocity (PWV) while Systemic Vascular Resistance (SVR) is increased. The model confirms that SVR plays a minimal role in terms of reflections. Reflections result from many reflections sites in the larger arteries. The lower PWV implies shorter wave length and thus artery length/wave length increases. This increase makes the differences in travel times from the many reflection sites to the heart more different resulting in lower total reflection: RM and AIx decrease. The lower PWV, thus the shorter wave length, also implies an increase in travel time over the aorta, and larger amplification. (It has been shown that local reflections change little with changes in stiffness.)

Conclusions: Reflections are mainly determined by travel times of reflected waves of the larger arteries. Mean pressure determines arterial stiffness and the stiffness change, via PWV, results in the opposite changes in RM and PPA.

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

References

1.JP Murgo, N Westerhof, JP Giolma, and SA Altobelli, Manipulation of ascending aortic pressure and flow wave reflections with the Valsalva maneuver: relationship to input impedance, Circulation, Vol. 63, 1981, pp. 122-32.
2.JP Murgo and N Westerhof, Arterial reflections and pressure wave forms in humans, FCP Yin (editor), Ventricular/Vascular Coupling, Spinger Verlag, London, 1987, pp. 140-158.
3.RD Latham, N Westerhof, P Sipkema, BJ Rubal, P Reuderink, and JP Murgo, Regional wave travel and reflections along the human aorta: a study with six simultaneous micromanometric pressures, Circulation, Vol. 72, 1985, pp. 1257-1269.
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Journal
Artery Research
Volume-Issue
20 - C
Pages
83 - 83
Publication Date
2017/12/06
ISSN (Online)
1876-4401
ISSN (Print)
1872-9312
DOI
10.1016/j.artres.2017.10.116How to use a DOI?
Open Access
This is an open access article distributed under the CC BY-NC license.

Cite this article

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TY  - JOUR
AU  - Nicolaas Westerhof
AU  - Berend Westerhof
PY  - 2017
DA  - 2017/12/06
TI  - P167 PULSE PRESSURE AMPLIFICATION AND AUGMENTATION INDEX CHANGE IN OPPOSITE MANNER WITH ARTERIAL STIFFNESS INDEPENDENTLY OF SYSTEMIC RESISTANCE
JO  - Artery Research
SP  - 83
EP  - 83
VL  - 20
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2017.10.116
DO  - 10.1016/j.artres.2017.10.116
ID  - Westerhof2017
ER  -