Torsional motion of the left ventricle does not affect ventricular fluid dynamics of both foetal and adult hearts

Vasudevan, Vivek; Wiputra, Hadi; Yap, Choon Hwai

doi:10.1016/j.jbiomech.2019.109357

Cited by 7 publications

(7 citation statements)

References 23 publications

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“…Simulating multiple cardiac cycles is a good practice to get rid of the transitional effects, as confirmed by several studies: Long et al ( 7 ), Vasudevan et al ( 29 ), Seo et al ( 4 ), Mangual et al ( 31 ), Chnafa et al ( 12 ) simulated 4, 4, 5, 10, 35 cycles, respectively. Among these, it is worth noticing that only Chnafa et al ( 12 ) reported the cycle-to-cycle variations in the wall shear stress of the diastasis during the 20th and 21st cycles.…”

Section: Discussionmentioning

confidence: 81%

“…In the referred case, five cycles were simulated to washout the initial conditions, and the results were reported based on phase-averaging over 30 additional cycles. In the other reported studies, even if multiple cycles were simulated, the analysis is often limited to the last cycle without reporting additional checks about the vanishing of the transient effects ( 4 , 7 , 29 , 31 ). More precise recommendations to objectively assess when a CFD calculation has reached a regime state may be helpful to the community.…”

Section: Discussionmentioning

confidence: 99%

“…The Chimera technique is particularly helpful when dealing with complex deforming geometries, and avoids complex remeshing of an ALE technique. A detailed description of the Chimera technique can be found in the Methods section of Canè et al ( 29 ).…”

Section: Methodsmentioning

confidence: 99%

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A CFD study on the interplay of torsion and vortex guidance by the mitral valve on the left ventricular wash-out making use of overset meshes (Chimera technique)

Canè

Delcour²,

Redaelli³

et al. 2022

Front. Med. Technol.

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Cardiovascular disease often occurs with silent and gradual alterations of cardiac blood flow that can lead to the onset of chronic pathological conditions. Image-based patient-specific Computational Fluid Dynamics (CFD) models allow for an extensive quantification of the flow field beyond the direct capabilities of medical imaging techniques that could support the clinicians in the early diagnosis, follow-up, and treatment planning of patients. Nonetheless, the large and impulsive kinematics of the left ventricle (LV) and the mitral valve (MV) pose relevant modeling challenges. Arbitrary Lagrangian-Eulerian (ALE) based computational fluid dynamics (CFD) methods struggle with the complex 3D mesh handling of rapidly moving valve leaflets within the left ventricle (LV). We, therefore, developed a Chimera-based (overset meshing) method to build a patient-specific 3D CFD model of the beating LV which includes a patient-inspired kinematic model of the mitral valve (LVMV). Simulations were performed with and without torsion. In addition, to evaluate how the intracardiac LV flow is impacted by the MV leaflet kinematics, a third version of the model without the MV was generated (LV with torsion). For all model versions, six cardiac cycles were simulated. All simulations demonstrated cycle-to-cycle variations that persisted after six cycles but were albeit marginal in terms of the magnitude of standard deviation of velocity and vorticity which may be related to the dissipative nature of the numerical scheme used. The MV was found to have a crucial role in the development of the intraventricular flow by enhancing the direct flow, the apical washout, and the propagation of the inlet jet towards the apical region. Consequently, the MV is an essential feature in the patient-specific CFD modeling of the LV. The impact of torsion was marginal on velocity, vorticity, wall shear stress, and energy loss, whereas it resulted to be significant in the evaluation of particle residence times. Therefore, including torsion could be considered in patient-specific CFD models of the LV, particularly when aiming to study stasis and residence time. We conclude that, despite some technical limitations encountered, the Chimera technique is a promising alternative for ALE methods for 3D CFD models of the heart that include the motion of valve leaflets.

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Section: Discussionmentioning

confidence: 81%

Section: Discussionmentioning

confidence: 99%

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A CFD study on the interplay of torsion and vortex guidance by the mitral valve on the left ventricular wash-out making use of overset meshes (Chimera technique)

Canè

Delcour²,

Redaelli³

et al. 2022

Front. Med. Technol.

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“…This twisting mechanism is associated with a momentum change of blood, which may affect intraventricular flow patterns ( 62 ). Yet, the influence of LV torsional motion onto flow and energy dynamics was investigated via image-based CFD by Vasudevan et al ( 63 ) and concluded to be insignificant. Similar results are reported from the image-based CFD model of Canè et al ( 64 ), where torsional motion did not influence energy loss and only slightly affected velocity, vorticity and wall shear stress.…”

Section: Discussionmentioning

confidence: 99%

CT-Based Analysis of Left Ventricular Hemodynamics Using Statistical Shape Modeling and Computational Fluid Dynamics

Goubergrits

Vellguth

Obermeier

et al. 2022

Front. Cardiovasc. Med.

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BackgroundCardiac computed tomography (CCT) based computational fluid dynamics (CFD) allows to assess intracardiac flow features, which are hypothesized as an early predictor for heart diseases and may support treatment decisions. However, the understanding of intracardiac flow is challenging due to high variability in heart shapes and contractility. Using statistical shape modeling (SSM) in combination with CFD facilitates an intracardiac flow analysis. The aim of this study is to prove the usability of a new approach to describe various cohorts.Materials and MethodsCCT data of 125 patients (mean age: 60.6 ± 10.0 years, 16.8% woman) were used to generate SSMs representing aneurysmatic and non-aneurysmatic left ventricles (LVs). Using SSMs, seven group-averaged LV shapes and contraction fields were generated: four representing patients with and without aneurysms and with mild or severe mitral regurgitation (MR), and three distinguishing aneurysmatic patients with true, intermediate aneurysms, and globally hypokinetic LVs. End-diastolic LV volumes of the groups varied between 258 and 347 ml, whereas ejection fractions varied between 21 and 26%. MR degrees varied from 1.0 to 2.5. Prescribed motion CFD was used to simulate intracardiac flow, which was analyzed regarding large-scale flow features, kinetic energy, washout, and pressure gradients.ResultsSSMs of aneurysmatic and non-aneurysmatic LVs were generated. Differences in shapes and contractility were found in the first three shape modes. Ninety percent of the cumulative shape variance is described with approximately 30 modes. A comparison of hemodynamics between all groups found shape-, contractility- and MR-dependent differences. Disturbed blood washout in the apex region was found in the aneurysmatic cases. With increasing MR, the diastolic jet becomes less coherent, whereas energy dissipation increases by decreasing kinetic energy. The poorest blood washout was found for the globally hypokinetic group, whereas the weakest blood washout in the apex region was found for the true aneurysm group.ConclusionThe proposed CCT-based analysis of hemodynamics combining CFD with SSM seems promising to facilitate the analysis of intracardiac flow, thus increasing the value of CCT for diagnostic and treatment decisions. With further enhancement of the computational approach, the methodology has the potential to be embedded in clinical routine workflows and support clinicians.

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“…Detailed structures of the LV and MV apparatus, such as chordae, papillary muscles, and trabeculae, are neglected. Note that LV torsion has, according to the work of Vasudevan et al ( 44 ) and Canè et al ( 45 ), no crucial influence on the investigated parameters and has not been included in the model. Manual interaction in the segmentation process can moreover lead to user-dependent uncertainties which may influence the CFD results.…”

Section: Discussionmentioning

confidence: 99%

Effect of transcatheter edge-to-edge repair device position on diastolic hemodynamic parameters: An echocardiography-based simulation study

Vellguth

Barbieri

Reinthaler

et al. 2022

Front. Cardiovasc. Med.

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BackgroundTranscatheter edge-to-edge repair (TEER) has developed from innovative technology to an established treatment strategy of mitral regurgitation (MR). The risk of iatrogenic mitral stenosis after TEER is, however, a critical factor in the conflict of interest between maximal reduction of MR and minimal impairment of left ventricular filling. We aim to investigate systematically the impact of device position on the post treatment hemodynamic outcome by involving the patient-specific segmentation of the diseased mitral valve.Materials and methodsTransesophageal echocardiographic image data of ten patients with severe MR (age: 57 ± 8 years, 20% female) were segmented and virtually treated with TEER at three positions by using a position based dynamics approach. Pre- and post-interventional patient geometries were preprocessed for computational fluid dynamics (CFD) and simulated at peak-diastole with patient-specific blood flow boundary conditions. Simulations were performed with boundary conditions mimicking rest and stress. The simulation results were compared with clinical data acquired for a cohort of 21 symptomatic MR patients (age: 79 ± 6 years, 43% female) treated with TEER.ResultsVirtual TEER reduces the mitral valve area (MVA) from 7.5 ± 1.6 to 2.6 ± 0.6 cm2. Central device positioning resulted in a 14% smaller MVA than eccentric device positions. Furthermore, residual MVA is better predictable for central than for eccentric device positions (R2 = 0.81 vs. R2 = 0.49). The MVA reduction led to significantly higher maximal diastolic velocities (pre: 0.9 ± 0.2 m/s, post: 2.0 ± 0.5 m/s) and pressure gradients (pre: 1.5 ± 0.6 mmHg, post: 16.3 ± 9 mmHg) in spite of a mean flow rate reduction by 23% due to reduced MR after the treatment. On average, velocities were 12% and pressure gradients were 25% higher with devices in central compared to lateral or medial positions.ConclusionVirtual TEER treatment combined with CFD is a promising tool for predicting individual morphometric and hemodynamic outcomes. Such a tool can potentially be used to support clinical decision making, procedure planning, and risk estimation to prevent post-procedural iatrogenic mitral stenosis.

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Torsional motion of the left ventricle does not affect ventricular fluid dynamics of both foetal and adult hearts

Cited by 7 publications

References 23 publications

A CFD study on the interplay of torsion and vortex guidance by the mitral valve on the left ventricular wash-out making use of overset meshes (Chimera technique)

A CFD study on the interplay of torsion and vortex guidance by the mitral valve on the left ventricular wash-out making use of overset meshes (Chimera technique)

CT-Based Analysis of Left Ventricular Hemodynamics Using Statistical Shape Modeling and Computational Fluid Dynamics

Effect of transcatheter edge-to-edge repair device position on diastolic hemodynamic parameters: An echocardiography-based simulation study

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