Impact of Long Duration Space Flight on Cardiac Structure and Function

As astronauts venture farther into space, the impact of long-term microgravity on cardiovascular function may become a critical limitation to mission safety and success. In order to better understand the impact of long-term spaceflight on the structure and function of the heart, the PI is already involved in echocardiographic analysis of the most detailed study of the heart in space ever undertaken. Unfortunately, the echocardiograph on the International Space Station is more than a decade old and does not provide contemporary information on cardiac function, such as strain (the best measure of regional and global contraction of the muscle) and torsion (the twisting motion of the heart that links the pumping and filling functions of the ventricle). Our first task in this proposal is to develop and validate methodology to extract strain and torsion from space station echoes and then combine it with the numerous pre- and post-flight studies that will be conducted over the next four years. From these data, we will have a comprehensive view of the heart in space, information which will be integrated into evolving mathematical models of the heart that the PI and collaborators have developed, and which will be made available to the general NASA community via integration into the Digital Astronaut project. Finally, the PI and colleagues are involved extensively in the development of the next generation of echo machines and have the unique opportunity to develop and validate advanced applications for space use. We will focus on massively parallelized echo machines capable of real-time 3D imaging with automated volume measurements and comprehensive 3D strain and torsion analysis. As these machines become smaller over time, they will provide the ideal diagnostic tool for future space missions, be they to a low earth orbit, a Lagrangian point, the moon, or even Mars.