Applied Fluid-Structure Interaction Technique to Initial Insight into the Effect of Exercise on the Aortic Valve Stroke Work

Seyed Javad Amirfakhri³, Hadi Shojaei⁴, Kamran Hassani⁵, Hossein Derakhshandeh⁶

¹Mechanical Engineering Department, San Diego State University, San Diego, 92182, CA, USA

²Department of Mechanical Engineering, Tennessee Technological University, Cookeville, TN 38505, USA

³Mechanical Engineering Department, Cal Poly Pomona, Pomona, CA 91768, USA

⁴Department of Pathology, University Hospitals Case Medical Center, Case Western Reserve University, Cleveland, OH 44106,USA

⁵Department of Biomechanics, Science and Research Branch, Islamic Azad University, Tehran, Iran

⁶Department of Mechanical & Material Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA

^*Corresponding Author

¹Hamidreza Ghasemi Bahraseman

Mechanical Engineering Department,

San Diego State University,

San Diego, 92182, CA, USA

Phone: (901) 567-8750

Fax: (931) 372-6340

Email:hghasemibahraseman@sdsu.edu

²Ehsan Mohseni Languri

Department of Mechanical Engineering,

Tennessee Technological University,

Cookeville, TN 38505, USA

Phone: (931) 372-6790

Fax: (931) 372-6340

Email:ELanguri@tntech.edu

Abstract

The left ventricular stroke work is a measure of the work done by the left ventricle during the ejection of blood throughout per cardiac cycle. The aim of this investigation was to propose a model to numerically evaluate the stroke work for a healthy subject using a fluid-structure interaction (FSI) simulation during exercise protocol. Aortic valve dimensions were calculated using an imaging technique of echocardiography. A FSI simulation was performed using an Arbitrary Lagrangian-Eulerian (ALE) mesh. Boundary conditions were defined by pressure loads on ventricular and aortic sides. Stroke work was predicted to increase to 121% from 60 bpm to 125 bpm, and it did not increase much above 125 bpm. Based on derived regression equations of our FSI results of stroke work and comparing them with clinical ones, numerically-predicted stroke work values are in good agreements with published clinical data. The slope of stroke work changes to mean arterial pressure, while exercise protocol, is 168.08 ml which is 12.2% less than the average slope of clinical data. The y-axis intercepted of stroke work changes to mean arterial pressure, while exercise protocol, is -11186 which is 15% less than the average y-axis intercept of clinical data. Our results of the specific patient show that numerical methods can be proposed to predict good estimates of patient specific stroke work at different heart rates.

Keywords:Aortic valve, Finite element method, Fluid solid interaction, Stroke work

Download the full article (PDF)