Exposure to long periods of microgravity in space can cause an astronaut's heart to change its shape, prompting the risk of suffering serious heart attacks, Business Standard reported.
A study of 12 astronauts spending time in space showed how their hearts can become more spherical, according to new findings.
According to Times of India, investing 18 months or more of their life in a spaceflight can end up affecting an astronauts' heart health, researchers said.
"The heart doesn't work as hard in space, which can cause a loss of muscle mass," said James Thomas, Moore Chair of Cardiovascular Imaging and Lead Scientist for Ultrasound at NASA, and senior author of the study.
"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," Thomas said.
"The results show the heart in space becomes more spherical by a factor of 9.4 per cent, a transformation similar to what scientists had predicted with sophisticated mathematical models developed for the project," Times of India reported.
Making use of ultrasound machines installed on the International Space Station, astronauts were trained by the research team to capture images of their hearts.
Data was provided by twelve astronauts during and after spaceflight.
In order to guarantee the safety of an astronaut's health on a long mission, a perfect balance of the type and amount of exercises required need to be analyzed and understood for the heart to be remain healthy.
However, the heart spherical heart shape tends to be temporary as it returns to its normal elongated shape on Earth.
Although the long-term health effects of the shape change are still unknown, the more spherical shape experienced in space may mean the heart is performing less efficiently, Business Standard reported.
"Thomas added that exercise regimens developed for astronauts could also be used to help maintain heart health in people on Earth who have severe physical limitations, such as people on extended bed rest or those with heart failure," Business Standard reported.
A more accurate and better understanding of common cardiovascular conditions in patients on Earth could also be understood through the validation of these study models.
"The models predicted the changes we observed in the astronauts almost exactly. It gives us confidence that we can move ahead and start using these models for more clinically important applications on Earth, such as to predict what happens to the heart under different stresses," Thomas said.
The study is to be presented at a meeting of the American College of Cardiology.
