Microgravity Affects Astronauts’ Heart Health During Space Travel

Today at the American College of Cardiology's 63^rd Annual Scientific Session a study will be presented about the heart health of astronauts who have been exposed to long periods of microgravity in space.

Senior author of the study, James Thomas, M.D., is the Moore Chair of Cardiovascular Imaging and Lead Scientist for Ultrasound. He and his researchers examined 12 astronauts to determine their heart health after spending an extensive period of time in space. They found that the heart becomes more spherical during spaceflights of 18 months or longer.

"The heart doesn't work as hard in space, which can cause a loss of muscle mass," said Dr. Thomas in this EurekAlert! news release. "That can have serious consequences after the return to Earth, so we're looking into whether there are measures that can be taken to prevent or counteract that loss."

For the study, the 12 astronauts were trained to take images of their hearts through the use of ultrasound machines that were installed on the International Space Station. Images were taken before, during, and after the spaceflight missions, and revealed that the heart becomes more spherical by a factor of 9.4% while in space.

However, the spherical shape is temporary the researchers say, as the heart returns to it's normal shape upon returning to Earth. Outer space has other various adverse effects on the human heart, including orthostatic hypotension, arrhythmias, and a possibility of accelerated atherosclerosis.

The researchers as well as other doctors plan to examine these effects on the heart as well as other cardiovascular effects that space may have on the vital organ. They're trying to develop exercise regimens for the astronauts in order for them to maintain a healthy heart during extended spaceflight missions. The upcoming Mars missions are of paramount concern for the researchers and doctors because such a long flight will undoubtedly cause various health issues for the astronauts.

To read more about outer space's effects on the human heart, visit this EurekAlert! news release.