Three-dimensional structure of the flow inside the left ventricle of the human heart

Fortini, Stefania; Querzoli, Giorgio; Espa, Stefania; Cenedese, A.

doi:10.1007/s00348-013-1609-0

Cited by 34 publications

(27 citation statements)

References 43 publications

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“…The current flow solver has been successfully applied to cardiac flows in a number of previous studies (8,(37)(38)(39)(47)(48)(49) and has been shown to generate flow features that are inline with in vivo observations (38). A recent validation study (46) for a model ventricle (15) with the same procedure also confirmed that our computational modeling procedure does produce the key features of the velocity and vorticity fields observed in ventricular flows. These previous simulations also provide guidance on the resolution required to model these flows.…”

Section: Methodssupporting

confidence: 59%

See 1 more Smart Citation

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

Seo

Abd

George

et al. 2016

American Journal of Physiology-Heart and Circulatory Physiology

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Seo JH, Abd T, George RT, Mittal R. A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles. Am J Physiol Heart Circ Physiol 310: H1567-H1582, 2016. First published March 25, 2016; doi:10.1152/ajpheart.00855.2015.-A coupled chemo-fluidic computational model for investigating flowmediated thrombogenesis in infarcted left ventricles (LVs) is proposed. LV thrombus (LVT) formation after the acute myocardial infarction (AMI) may lead to thromboembolic events that are associated with high mortality and morbidity, and reliable stratification of LVT risk is the key to managing the treatment of AMI patients. There have been several studies emphasizing the importance of LV blood flow patterns on thrombus formation; however, given the complex interplay between ventricular flow dynamics and biochemistry of thrombogenesis, current understanding is mostly empirical. In the present model, blood flow in the LV is obtained by solving the incompressible Navier-Stokes equations, and this is coupled to the biochemical modeling of the coagulation cascade, platelet activation, and fibrinogen polymerization. The coupled model is used to examine the effect of ventricular flow patterns on thrombogenesis in modeled ventricles. It is expected that the method developed here will enable in-depth studies of thrombogenesis in patient-derived infarcted LV models. computational hemodynamics; cardiac flow; intraventricular flow; blood clot; coagulation cascade; biochemical reaction NEW & NOTEWORTHY A computational method that simultaneously resolves the left ventricular flow patterns as well as the biochemical coagulation cascade (CC) is proposed. The method enables a clear identification of the effect of flow patterns on left ventricular thrombogenesis and suggests a metric quantitatively correlated to thrombogenic risk.ONE OF THE MOST FEARED COMPLICATIONS for patients with acute myocardial infarction (AMI) is the occurrence of thromboembolic events associated with left ventricular (LV) thrombus (LVT) formation (11) and cardioembolic strokes, which account for 20 -30% of all ischemic strokes (25,27,33). The identification of high-risk patients and the pharmacological prevention of LVT formation are the keys to preventing these embolic events. Thrombus formation results from the combination of disturbed blood flow patterns, endothelial injury, and hypercoagulability of the endothelium. After AMI, LV regional wall akinesia or dyskinesia changes the patterns of blood flow in the LV, and this can result in local stasis of blood flow (3). Prolonged ischemia also leads to subendocardial tissue injury with inflammatory changes and may lead to the development of a LV aneurysm (30, 34), which may cause further abnormalities in LV flow. Furthermore, patients with acute coronary syndrome show a hypercoagulable state with increased concentrations of prothrombin and fibrinopeptide (11). The above prerequisites in the LV with AMI lead to the formation of LVT composed of fibrin, platelets, and red blood cells.Risk factors f...

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Section: Methodssupporting

confidence: 59%

“…Healthy LVs generate vortexes that are by now well characterized (13,15,37), and the flow and dissipation induced by ventricular vortexes are expected to play a key role in modulating the conditions for thrombogenesis in infarcted ventricles. In the present study, 3D vortical structures are identified by the well-established Q-criterion (20).…”

Section: Methodsmentioning

confidence: 99%

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

Seo

Abd

George

et al. 2016

American Journal of Physiology-Heart and Circulatory Physiology

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“…The process repeats during the A-wave, with a new injection of momentum that further strengthens the large-scale vortex. This recirculation lasts for a large fraction of the cycle (approximately 50 %), and it is very beneficial for the haemodynamics since it constantly sweeps the endocardium and prevents the formation of stagnant flow regions (Fortini et al 2013). When the systole starts, the flow leaves the ventricle from both the aortic and the mitral channel.…”

Section: Flow Induced By Natural and Prosthetic Mitral Valvesmentioning

confidence: 99%

Flow structure in healthy and pathological left ventricles with natural and prosthetic mitral valves

Meschini

Tullio²,

Querzoli

et al. 2017

J. Fluid Mech.

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In this paper, the structure and the dynamics of the flow in the left heart ventricle are studied for different pumping efficiencies and mitral valve types (natural, biological and mechanical prosthetic). The problem is investigated by direct numerical simulation of the Navier-Stokes equations, two-way coupled with a structural solver for the ventricle and mitral valve dynamics. The whole solver is preliminarily validated by comparisons with ad hoc experiments. It is found that the system works in a highly synergistic way and the left ventricular flow is heavily affected by the specific type of mitral valve, with effects that are more pronounced for ventricles with reduced pumping efficiency. When the ventricle ejection fraction (ratio of the ejected fluid volume to maximum ventricle volume over the cycle) is within the physiological range (50 %-70 %), regardless of the mitral valve geometry, the mitral jet sweeps the inner ventricle surface up to the apex, thus preventing undesired flow stagnation. In contrast, for pathological ejection fractions ( 40 %), the flow disturbances introduced by the bileaflet mechanical valve reduce the penetration capability of the mitral jet and weaken the recirculation in the ventricular apex. Although in clinical practice the fatality rates in the five-year follow-ups for mechanical and biological mitral valve replacements are essentially the same, a breakdown of the deaths shows that the causes are very different for the two classes of prostheses and the present findings are consistent with the clinical data. This might have important clinical implications for the choice of prosthetic device in patients needing mitral valve replacement.

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“…This method has already been used in several studies (e.g. Cenedese et al 2005;Fortini et al 2013); details can be found in Miozzi et al (2008).…”

Section: Figmentioning

confidence: 99%

Water-Channel Study of Flow and Turbulence Past a Two-Dimensional Array of Obstacles

Bernardino

Leuzzi

Querzoli

2015

Boundary-Layer Meteorol

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A neutral boundary layer was generated in the laboratory to analyze the mean\ud velocity field and the turbulence field within and above an array of two‐dimensional obstacles\ud simulating an urban canopy. Different geometrical configurations were considered in order to\ud investigate the main characteristics of the flow as a function of the aspect ratio (AR) of the canopy.\ud To this end, a summary of the two‐dimensional fields of the fundamental turbulence parameters is\ud given for AR ranging from 1 to 2. The results show that the flow field depends strongly on AR only\ud within the canyon, while the outer flow seems to be less sensitive to this parameter. This is not\ud true for the vertical momentum flux, which is one of the parameters most affected by AR, both\ud within and outside the canyon. The experiments also indicate that, when (i.e. the\ud skimming flow regime), the roughness sub‐layer extends up to a height equal to 1.25 times the\ud height of the obstacles (H), surmounted by an inertial sub‐layer that extends up to 2.7 H. In\ud contrast, for (i.e. the wake‐interference regime) the inertial sub‐layer is not present.\ud This has significant implications when using similarity laws for deriving wind and turbulence\ud profiles in canopy flows. Furthermore, two estimations of the viscous dissipation rate of turbulent\ud kinetic energy of the flow are given. The first one is based on the fluctuating strain rate tensor,\ud while the second is related to the mean strain rate tensor. It is shown that the two expressions\ud give similar results, but the former is more complicated, suggesting that the latter might be used\ud in numerical models with a certain degree of reliability. Finally, the data presented can also be\ud used as a dataset for the validation of numerical models

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Three-dimensional structure of the flow inside the left ventricle of the human heart

Cited by 34 publications

References 43 publications

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

A coupled chemo-fluidic computational model for thrombogenesis in infarcted left ventricles

Flow structure in healthy and pathological left ventricles with natural and prosthetic mitral valves

Water-Channel Study of Flow and Turbulence Past a Two-Dimensional Array of Obstacles

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