Topics

A 4D Flow MRI Evaluation of the Impact of Shear-Dependent Fluid Viscosity on in vitro Fontan Circulation Flow.

08:00 EDT 4th October 2019 | BioPortfolio

Summary of "A 4D Flow MRI Evaluation of the Impact of Shear-Dependent Fluid Viscosity on in vitro Fontan Circulation Flow."

The Fontan procedure for univentricular heart defects creates a non-physiologic circulation where systemic venous blood drains directly into the pulmonary arteries, leading to multiorgan dysfunction secondary to chronic low-shear non-pulsatile pulmonary blood flow and central venous hypertension. Although blood viscosity increases exponentially in this low-shear environment, the role of shear-dependent ("non-Newtonian") blood viscosity in this pathophysiology is unclear. We studied 3D-printed Fontan models in an in vitro flow loop with a Philips 3T MRI scanner. A 4D flow phase-contrast sequence was used to acquire a time-varying 3D velocity field for each experimental condition. Based on blood viscosity of a Fontan patient cohort, 0.04% xanthan gum was used as a non-Newtonian blood analog; 45% glycerol was used as a Newtonian control fluid. MRI data was analyzed using GTFlow and Matlab software. The primary outcome, power loss, was significantly higher with the Newtonian fluid (14.8% [13.3%,16.4%] vs. 8.1% [6.4%,9.8%], p<0.0001). The Newtonian fluid also demonstrated marginally higher right pulmonary artery flow, marginally lower shear stress, and a trend toward higher caval flow mixing. Outcomes were modulated by Fontan model complexity, cardiac output, and caval flow ratio. Vortices, helical flow, and stagnant flow were more prevalent with the non-Newtonian fluid. Our data demonstrates that shear-dependent viscosity significantly alters qualitative flow patterns, power loss, pulmonary flow distribution, shear stress, and caval flow mixing in synthetic models of the Fontan circulation. Potential clinical implications include effects on exercise capacity, ventilation/perfusion matching, risk of pulmonary arteriovenous malformations, and risk of thromboembolism.

Affiliation

Journal Details

This article was published in the following journal.

Name: American journal of physiology. Heart and circulatory physiology
ISSN: 1522-1539
Pages:

Links

DeepDyve research library

PubMed Articles [27536 Associated PubMed Articles listed on BioPortfolio]

Rheology of active polar emulsions: from linear to unidirectional and inviscid flow, and intermittent viscosity.

The rheological behaviour of an emulsion made of an active polar component and an isotropic passive fluid is studied by lattice Boltzmann methods. Different flow regimes are found by varying the value...

Visualizing protein motion in Couette flow by all-atom molecular dynamics.

In living cells, biomacromolecules are exposed to a highly crowded environment. The cytoplasm, the nucleus, and other organelles are highly viscous fluids that differ from dilute in vitro conditions. ...

Characterization of the Hydrodynamics in the USP Basket Apparatus using Computational Fluid Dynamics.

Computational fluid dynamics (CFD) has been extensively used for the USP paddle apparatus II but limited CFD studies have been conducted on the USP basket apparatus I. We expanded on past CFD basket s...

Theoretical and numerical investigation of Carreau-Yasuda fluid flow subject to Soret and Dufour effects.

Newtonian fluids can be categorized by a single coefficient of viscosity for specific temperature. This viscosity will change with temperature; it doesn't change with strain rate. Just a small group o...

The presence of helical flow can suppress areas of disturbed shear in parameterised models of an arteriovenous fistula.

Areas of disturbed shear that develop following arteriovenous fistula (AVF) creation are believed to trigger the onset of intimal hyperplasia (IH), leading to AVF dysfunction. The presence of helical ...

Clinical Trials [11369 Associated Clinical Trials listed on BioPortfolio]

Impact of Acute Normovolemic Hemodilution on Blood Viscosity

Acute normovolemic hemodilution (ANH) has long been employed for reducing allogenic blood transfusion for cardiac surgery, and hydroxyethyl starch has been used as an intravenous replaceme...

Tympanostomy Tube Extrusion Time & Viscosity

Studies have focused on the factors that influence tympanostomy tube (TT) extrusion may contribute to the management of OME. In this study the investigators aimed to assess the correlation...

Fluid Responsiveness Tested by the Effective Pulmonary Blood Flow During a Positive End-expiratory Trial

Fluid responsiveness is difficult to assess at the bedside. The accuracy of published techniques to detect preload-dependent patients have many pitfalls and limitations. The present study ...

Relationship Between Fractional Flow Reserve/ Instantaneous Wave Free Ratio and Endothelial Wall Shear Stress

This study, designed as a retrospective registry, aims to investigate the relationship and potential interplay between fractional flow reserve (FFR) or instantaneous waves free ratio (iFR)...

Dapagliflozin vs Empagliflozin on Flow Mediated Dilation in Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a considered one of the main global health challenges; the vascular endothelium plays an important role in vascular dysfunction in DM; Hyperglycemia indu...

Medical and Biotech [MESH] Definitions

The internal resistance of the BLOOD to shear forces. The in vitro measure of whole blood viscosity is of limited clinical utility because it bears little relationship to the actual viscosity within the circulation, but an increase in the viscosity of circulating blood can contribute to morbidity in patients suffering from disorders such as SICKLE CELL ANEMIA and POLYCYTHEMIA.

The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

The study of the deformation and flow of matter, usually liquids or fluids, and of the plastic flow of solids. The concept covers consistency, dilatancy, liquefaction, resistance to flow, shearing, thixotrophy, and VISCOSITY.

Studies designed to assess the efficacy of programs. They may include the evaluation of cost-effectiveness, the extent to which objectives are met, or impact.

The internal resistance of a material to moving some parts of it parallel to a fixed plane, in contrast to stretching (TENSILE STRENGTH) or compression (COMPRESSIVE STRENGTH). Ionic crystals are brittle because, when subjected to shear, ions of the same charge are brought next to each other, which causes repulsion.

Quick Search


DeepDyve research library

Relevant Topics

Radiology
Radiology is the branch of medicine that studies imaging of the body; X-ray (basic, angiography, barium swallows), ultrasound, MRI, CT and PET. These imaging techniques can be used to diagnose, but also to treat a range of conditions, by allowing visuali...

Cardiology
Cardiology is a specialty of internal medicine.  Cardiac electrophysiology : Study of the electrical properties and conduction diseases of the heart. Echocardiography : The use of ultrasound to study the mechanical function/physics of the h...

Pulmonary
Pulmonary relating to or associated with the lungs eg Asthma, chronic bronchitis, emphysema, COPD, Cystic Fibrosis, Influenza,  Lung Cancer, Pneumonia, Pulmonary Arterial Hypertension, Sleep Disorders etc Follow and track Lung Cancer News ...


Searches Linking to this Article