Phasic coronary artery flow velocity determined by Doppler flowmeter catheter in aortic stenosis and aortic regurgitation

Matsuo, Shuzo; Tsuruta, Mitsuhiro; Hayano, Motonobu; Imamura, Youichi; Eguchi, Yoshiki; Tokushima, Takashi; Tsuji, Shinsuke

doi:10.1016/0002-9149(88)90893-4

Cited by 59 publications

(35 citation statements)

References 23 publications

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“…At the outlet of the artery, the velocities are free, but the normal and tangential shear stresses are constrained to be zero and the gauge pressure is also set to zero. At the inlet of the artery a uniform inlet velocity profile with the time varying forcing function (or velocity multiplier) given in Figure 4 is assumed (Matsuo et al, 1988, Figure 4A). This physiological profile was recorded in the right coronary artery of a normal 56-year-old female and contains some periods of reverse flow as well as periods of rapid acceleration and deceleration.…”

Section: Modellingmentioning

confidence: 99%

Non-Newtonian blood flow in human right coronary arteries: steady state simulations

Johnston

Corney

et al. 2004

Journal of Biomechanics

572

349

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This study looks at pulsatile blood flow through four different right coronary arteries, which have been reconstructed from bi-plane angiograms. A non-Newtonian blood model (the Generalised Power Law), as well as the usual Newtonian model of blood viscosity, is used to study the wall shear stress in each of these arteries over the entire cardiac cycle. The difference between Newtonian and non-Newtonian blood models is also studied over the whole cardiac cycle using the recently generalised global non-Newtonian importance factor. In addition, the flow is studied by considering paths of massless particles introduced into the flow field.The study shows that, when studying the wall shear stress distribution for transient blood flow in arteries, the use of a Newtonian blood model is a reasonably good approximation. However, to study the flow within the artery in greater detail, a non-Newtonian model is more appropriate.

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Section: Modellingmentioning

confidence: 99%

Non-Newtonian blood flow in human right coronary arteries: steady state simulations

Johnston

Corney

et al. 2004

Journal of Biomechanics

572

349

View full text Add to dashboard Cite

show abstract

“…Pulsatile simulations used a physiologically realistic flow waveform with mean Reynolds number of 233 and a Womersley parameter of 1.82. 14 Measured flow rates entering each branch were not available. Therefore, flow rates in each branch were computed using a third The casts were CT-scanned and segmented to obtain crosssectional contours (center) of each artery trunk and its larger branches.…”

Section: Computational Fluid Dynamicsmentioning

confidence: 99%

Intimal Thickness Is not Associated With Wall Shear Stress Patterns in the Human Right Coronary Artery

Joshi

Leask²,

Myers³

et al. 2004

ATVB

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Objective-Low wall shear stress has been implicated in atherogenesis throughout the arterial tree, including the right coronary artery (RCA). The objective of this study was to determine the level of covariation of intimal thickness and wall shear stress in the human RCA. Methods and Results-Postmortem histological measurements of intimal thickness were compared with wall shear stresses calculated from computational flow modeling in 4 human right coronary arteries. A statistically significant correlation between intimal thickness and wall shear stress was found in only 1 of the 4 arteries studied. 1 This has led to a "geometric risk factor" hypothesis implicating local hemodynamic factors in atherogenesis. 2 Studies have generally implicated low, or low and oscillating, wall shear stress (WSS) in atherogenesis. 1,[3][4][5][6] Asakura and Karino 1 were the first to report an association between low WSS and intimal thickening in the right coronary artery (RCA). Subsequently, Krams et al 7 showed that RCA locations with lower average WSS had higher average wall thickness; however, their study did not explicitly show that low WSS colocalized with high wall thickness, because of the axial averaging technique they used. Giannoglou et al found an inverse correlation between wall thickness and WSS in 1 of 3 RCA segments. 8 Their study was limited to a 2-dimensional computational analysis to obtain WSS, which neglects important secondary flow hemodynamic effects that significantly affect WSS patterns. 9 Stone et al also found that, on average, regions of low WSS showed an increase in plaque thickness, whereas regions of high WSS showed a decrease in plaque thickness. This study followed plaque progression in vivo in segments of the right and left coronary arteries of 6 patients over a 6-month period. 10 Wentzel et al 11 found an inverse relationship between WSS and intimal thickening in coronary arteries, but only in vessel segments that showed Ͻ10% lumen area reduction. Conclusion-WallIf low (or low and oscillating) WSS is atherogenic in the RCA, as is frequently claimed in the literature, then we reasoned that there should be an evident colocalization of intimal thickness and low WSS. Most importantly, this correlation should be statistically significant when tested on a point-by-point basis over the entire RCA. To date, no study has looked for such a correlation in a quantitative manner over the entire artery.The objective of this study was to determine whether a significant correlation between intimal thickness and WSS exists in the RCA. To do so, we compared postmortem histological measurements of intimal thickness (IT) to WSS calculated from computational flow modeling in 4 RCAs. Methods Coronary Artery CastingFour intact human hearts were obtained at autopsy from patients whose primary cause of death was not cardiac-related (Table). Patient medical records indicated that patients 2, 3,and 4 were smokers, and patient 2 had hypertension. No other systemic risk factors for atherosclerosis (diabetes, hyperlipidemia, ...

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“…For an arbitrary deformable control volume V(t), the non-dimensionalized governing equations are (2 Fig. 3 Volumetric flow rate waveform imposed on inlet as a Dirichlet boundary condition, which was extracted from Matsuo, et al, (1988). The flow rate waveform was normalized by mean flow rate Q mean =1.65 [ml/s].…”

Section: Computational Fluid Dynamic Modeling Of Blood Flows In Coronmentioning

confidence: 99%

“…A volumetric flow rate waveform imposed on inlet as a boundary condition was extracted from Matsuo, et al, (1988), which had been measured in a normal female with Doppler flow-meter catheter (Fig. 3).…”

Section: Es Edmentioning

confidence: 99%

“…During diastole, the coronary pressure decreases with the resistance lowered in distal capillary arteries leads to reducing the diameter of right coronary artery and hence increasing the coronary blood flow (Weissman, et al, 1995;Westerhof, et al, 2006;Zeng, et al, 2008). Velocity vectors and WSSs associated with the three models without Matsuo, et al, (1988) (Fig. 3); B is extracted from Atbek et al, (1975); and C is 180° phase-delayed waveform of A.…”

Section: Effects Of Vessel Dynamics and Compliance On Coronary Arterymentioning

confidence: 99%

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Effects of vessel dynamics and compliance on human right coronary artery hemodynamics with / without stenosis

Fujiwara

Liang

Tsubota

et al. 2015

JBSE

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A computational study of effects of vessel dynamics and compliance on coronary artery hemodynamics with / without stenosis is presented. The coronary artery hemodynamics with stenosis has been a main subject as one of the major cardiovascular diseases induced by atherosclerosis; most computational models assume that the vessel movement and deformation are negligible (Zeng, et al., 2003;Kim, et al., 2010). However, it is still unclear whether the hemodynamic characteristics owning to vessel dynamics and compliance are clinically significant or not particularly under pathological conditions. In this study, we aim at investigating the hemodynamic effects of the vessel dynamics and compliance in right coronary artery under healthy situation without stenosis as well as under diseased conditions with stenosis. We constructed a three-dimensional geometric model of the right coronary artery based on X-ray angiographic images, in which both vessel movement and deformation were taken into account. A specific volumetric flow rate was employed as a boundary condition imposed on inlet. Furthermore, we carried out an extensive study on the inlet waveform dependence and the effects of the vessel compliance on coronary hemodynamics. Our results demonstrate that the conventional assumption on 'rigid' artery models holds only in the cases of normal coronary arteries but fails for stenosed coronary arteries where the vessel dynamics and compliance do extend significant influence on distributions of the oscillatory shear indices (OSIs). Moreover, we find that the effects of vessel dynamics and compliance on coronary hemodynamics seem to be independent of both inlet boundary conditions and the vessel compliance.

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Phasic coronary artery flow velocity determined by Doppler flowmeter catheter in aortic stenosis and aortic regurgitation

Cited by 59 publications

References 23 publications

Non-Newtonian blood flow in human right coronary arteries: steady state simulations

Non-Newtonian blood flow in human right coronary arteries: steady state simulations

Intimal Thickness Is not Associated With Wall Shear Stress Patterns in the Human Right Coronary Artery

Effects of vessel dynamics and compliance on human right coronary artery hemodynamics with / without stenosis

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