HEART - Astronauts' hearts become more spherical in space

New findings from a study of 12 astronauts show the heart becomes more spherical when exposed to long periods of microgravity in space, a change that could lead to cardiac problems, according to research. With implications for an eventual manned mission to Mars, the findings represent an important step toward understanding how a spaceflight of 18 months or more could affect astronauts' heart health ...

http://www.sciencedaily.com/releases/2014/03/140329175106.ht