5.1 INERTIAL-VISCOELASTIC MINIMAL MODEL OF THE ARTERIAL SYSTEM RECONCILES ARTERIAL COMPLIANCE ESTIMATIONS

DOI

10.1016/j.artres.2015.10.026How to use a DOI?

Abstract

Background: The arterial system is viscoelastic rather than purely elastic. There exist various methods to characterize the purely elastic nature of arterial compliance, each method yielding different values. The pulse pressure method (C_PPM), estimating compliance by matching the pulse pressure (PP) of a two-element Windkessel to measured PP, yields consistently lower values than the pressure decay time method (C_dec) and diastolic area method (C_area). An alternative inertial-viscoelastic model (IVEMM) that is viscoelastic and frequency-dependent rather than purely elastic and constant has been shown in dogs to reconcile the various compliance estimation methods. We assessed the presumed merits of IVEMM compliance estimates in a clinically diverse human sample.

Methods: Central pressure and flow were measured using carotid tonometry and phase-contrast MRI, respectively, in 226 subjects. Arterial compliance was estimated using (1) C_ppm; (2) C_dec; (3) C_area; (4) C_IVEMM(jω).

Results: C_ppm was nearly perfectly correlated with C_IVEMM evaluated at frequency of heart rate (Pearson coefficient (ρ) = 0.99; slope (B) = 1.00; P < 0.001). C_area (ρ = 0.979; B = 0.928; P < 0.001) and C_dec (ρ = 0.974; B = 0.954; P < 0.001) were very strongly correlated with C_IVEMM evaluated at 0 hertz (static compliance).

Conclusion: C_PPM is fit to PP defined in systole, when fast-acting phenomena are likely to elicit viscoelasticity of the arterial system. Its consistently lower values compared to C_dec and C_area are clarified by IVEMM to be the result of estimating viscoelastic compliance at frequency of heart rate. C_dec and C_area are estimates of static compliance. Consistent with dog studies, IVEMM appears to reconcile the three popular compliance estimation techniques.

Open Access

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

TY  - JOUR
AU  - Timothy Phan*
AU  - John Li
AU  - Maheshwara Koppula
AU  - Izzah Vasim
AU  - Swapna Varakantam
AU  - Julio Chirinos
PY  - 2015
DA  - 2015/11/23
TI  - 5.1 INERTIAL-VISCOELASTIC MINIMAL MODEL OF THE ARTERIAL SYSTEM RECONCILES ARTERIAL COMPLIANCE ESTIMATIONS
JO  - Artery Research
SP  - 45
EP  - 45
VL  - 12
IS  - C
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2015.10.026
DO  - 10.1016/j.artres.2015.10.026
ID  - Phan*2015
ER  -