Novel wave intensity analysis of arterial pulse wave propagation accounting for peripheral reflections

TY - JOUR

T1 - Novel wave intensity analysis of arterial pulse wave propagation accounting for peripheral reflections

AU - Alastruey, Jordi

AU - Hunt, Anthony A. E.

AU - Weinberg, Peter D.

PY - 2014/2

Y1 - 2014/2

N2 - We present a novel analysis of arterial pulse wave propagation that combines traditional wave intensity analysis with identification of Windkessel pressures to account for the effect on the pressure waveform of peripheral wave reflections. Using haemodynamic data measured in vivo in the rabbit or generated numer- ically in models of human compliant vessels, we show that traditional wave intensity analysis identifies the timing, direction and magnitude of the predominant waves that shape aortic pressure and flow wave- forms in systole, but fails to identify the effect of peripheral reflections. These reflections persist for several cardiac cycles and make up most of the pressure waveform, especially in diastole and early systole. Ignoring peripheral reflections leads to an erroneous indication of a reflection-free period in early systole and addi- tional error in the estimates of (i) pulse wave velocity at the ascending aorta given by the P U –loop method (9.5% error) and (ii) transit time to a dominant reflection site calculated from the wave intensity profile (27% error). These errors decreased to 1.3% and 10%, respectively, when accounting for peripheral reflec- tions. Using our new analysis, we investigate the effect of vessel compliance and peripheral resistance on wave intensity, peripheral reflections and reflections originating in previous cardiac cycles.

AB - We present a novel analysis of arterial pulse wave propagation that combines traditional wave intensity analysis with identification of Windkessel pressures to account for the effect on the pressure waveform of peripheral wave reflections. Using haemodynamic data measured in vivo in the rabbit or generated numer- ically in models of human compliant vessels, we show that traditional wave intensity analysis identifies the timing, direction and magnitude of the predominant waves that shape aortic pressure and flow wave- forms in systole, but fails to identify the effect of peripheral reflections. These reflections persist for several cardiac cycles and make up most of the pressure waveform, especially in diastole and early systole. Ignoring peripheral reflections leads to an erroneous indication of a reflection-free period in early systole and addi- tional error in the estimates of (i) pulse wave velocity at the ascending aorta given by the P U –loop method (9.5% error) and (ii) transit time to a dominant reflection site calculated from the wave intensity profile (27% error). These errors decreased to 1.3% and 10%, respectively, when accounting for peripheral reflec- tions. Using our new analysis, we investigate the effect of vessel compliance and peripheral resistance on wave intensity, peripheral reflections and reflections originating in previous cardiac cycles.

KW - haemodynamics

KW - pulse wave propagation

KW - wave intensity analysis

KW - one-dimensional mod- elling;

KW - Windkessel effect

KW - PU-loop method

KW - systemic circulation

U2 - 10.1002/cnm.2602

DO - 10.1002/cnm.2602

M3 - Article

SN - 2040-7939

VL - 30

SP - 249

EP - 279

JO - International Journal For Numerical Methods In Biomedical Engineering

JF - International Journal For Numerical Methods In Biomedical Engineering

IS - 2

ER -