MS NASA EPSCoR RID Projects Analysis of the Mechanisms of Cardiac Function and Rhythm Problems During Spaceflight There have been evidences of myocardial atrophy and associated cardiac dysrhythmias during prolonged spaceflight that are identified by NASA as a significant risk for future human space exploration (Platts, Summers et al. NASA’s HRP Evidence Books: NASA-TP:2010:1-17). The development of effective countermeasures requires a clear understanding of the biologic mechanisms driving the observed microgravity induced cardiac adaptations. Prior research had focused on pressuredriven stress changes as a driving mechanism. However, according to Laplace’s law for hollow chambers (tension pressure ∙ radius of curvature), the overall geometry of the ventricle and the resultant local wall radii of curvature are also important factors determining myocardial stress. A retrospective analysis of past spaceflight echocardiograms revealed that there are gravity dependent changes in the conformation of the ventricle that could alter the wall tension (Summers et al. Aviat Space Environ Med 2010;81:506510). We then constructed a finite element model (FEM) of the heart in microgravity to further investigate the hypothesis regarding the causal mechanism of spaceflight induced changes in ventricular shape and stress based on a shape change alone (Summers et al. ICES513 Proceedings 2012;20123448). A simulation of the ventricular electrical propagation grounded in the predicted microgravity induced remodeling of the FEM myocardium is being derived for an analysis of the potential for arrhythmogenesis and determine the proficiency of the twisting motion of the ventricle cycle as it relates to systolic and diastolic function. This adaptive functioning will also be integrated into a broader model of human physiology as a part of the NASA Digital Astronaut Project.
Dr. Richard Summers, Dept. of Emergency Medicine, University of Mississippi Medical Center
NASA EPSCoR Stimuli 2014 -15
Dr. Richard Summers, Department of Emergency Medicine, University of Mississippi Medical Center
Published on Dec 14, 2015
NASA Office of Education’s Aerospace Research & Career Development (ARCD) is pleased to release NASA EPSCoR Stimuli, a collection of univers...