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Fluid-Structure Interaction Modeling of Aortic Valve Stenosis at Different Heart Rates

Bahraseman H. G., Languri E. M., Yahyapourjalaly N., Espino D. M.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 3

11--20

EN

Purpose: This paper proposes a model to measure the cardiac output and stroke volume at different aortic stenosis severities using a fluid–structure interaction (FSI) simulation at rest and during exercise. Methods: The geometry of the aortic valve is generated using echocardiographic imaging. An Arbitrary Lagrangian–Eulerian mesh was generated in order to perform the FSI simulations. Pressure loads on ventricular and aortic sides were applied as boundary conditions. Results: FSI modeling results for the increment rate of cardiac output and stroke volume to heart rate, were about 58.6% and –14%, respectively, at each different stenosis severity. The mean gradient of curves of cardiac output and stroke volume to stenosis severity were reduced by 57% and 48%, respectively, when stenosis severity varied from healthy to critical stenosis. Conclusions: Results of this paper confirm the promising potential of computational modeling capabilities for clinical diagnosis and measurements to predict stenosed aortic valve parameters including cardiac output and stroke volume at different heart rates.

2

Analysis of actual accuracy in cardiac output measurements by means of thermodilution

Gawlikowski M., Pustelny T.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2012

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Vol. 60, nr 3

581-587

EN

The essential examination in hemodynamic monitoring of the patient is the cardiac output (CO) measurement. Nowadays, in clinical practice the most popular method is indicator dilution, particularly thermodilution. It is realized by applying the Swan-Ganz catheter and observing changes of the indicator concentration. This method is sensitive to many factors and the obtained results should be treated cautiously. The paper presents theoretical and experimental studies of metrological phenomena in CO measurements by means of thermodilution, paying special attention to medical aspects of the measurements. It has been pointed out that the actual unreliability of the mentioned method reaches values from 20% to 45%, which is in opposition to the technical data of patient's monitors (typical accuracy about 5%).

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A new noninvasive method of cardiac output determination. Principle of measurement

Szczepański A., Jastrzębski J., Pałko T., Książkiewicz A., Guć M.

Biocybernetics and Biomedical Engineering

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2000

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Vol. 20, no. 2

103-109

EN

We present the principles of on indicator method in which the indicator is either hypertonic salt solution or distilled water injected as a bolus into the venous system. The dilution curve is measured in temporal or limb artery by means of external reography.

PL

W artykule przedstawiono założenia zastosowania metody indykatorowej do pomiaru rzutu serca przy użyciu hiper- lub hipotonicznego roztworu soli fizjologicznej, u pacjentów w stanie krytycznym. Nieinwazyjny pomiar stężenia znacznika dokonywany jest metodą reograficzną z powierzchni skóry.