Microgravity Induced Changes in Left Ventricular Conformation in a Finite Element Model of the Heart
- Paper number
IAC-11,A1,2,17,x10686
- Author
Dr. Richard Summers, University of Mississippi, United States
- Coauthor
Mr. Weston Smith, University of Mississippi, United States
- Year
2011
- Abstract
{\bf Background:} There is concern regarding the long-term effects of microgravity exposure on cardiac function with some evidence of a loss of ventricular mass. According to Laplace’s law, the geometry of the ventricle is an important factor determining segmental wall stress and inducing alterations in the structure of the myocardium. If microgravity exposure results in a variation in the geometry of the ventricle, then we might also expect some cardiac remodeling during extended spaceflights. In this study we analyze the theoretical impact of microgravity on changes in the geometric conformation of a finite element model (FEM) of the left ventricle (LV) attributed with material properties consistent with myocardial tissue. {\bf Methods:} Mimics and 3-matic software were used to create a finite element mesh model of the heart using the 3-dimensional geometry acquired from CT scans, MRI scans, and cryosection images in the NIH Visible Human Project ® of the National Library of Medicine. The myocardial mesh was exported to ABAQUS for comparison analyses and the myocardial material properties were incorporated into the elements. The Geometric Aspect Ratios (GAR) of the left ventricle were calculated and compared as the LV length to width quotient during simulations of the upright anatomic diastolic position in Earth’s gravity and in microgravity. {\bf Results: } The theoretical application of microgravity to the FEM model of the heart resulted in a 3.6\% lower GAR of the LV as compared to that calculated for Earth’s gravity while the overall volume remained stable. {\bf Conclusions:} The geometry of the heart and its impact on the segmental wall stress are a known driving force for cardiac remodeling. This study examined the theoretical impact of microgravity exposure on the shape of the LV. Changes in ventricular sphericity associated with local changes in the radius of curvature of the myocardial wall were observed in simulated microgravity.- Abstract document
- Manuscript document
(absent)