Have A Heart! This Organ Plays Shape-Shifter In Space, Leading To Mars Mission Questions

by Elizabeth Howell on March 31, 2014

Astronaut Piers Sellers during an STS-121 spacewalk in 2006 to demonstrate techniques on repairing the shuttle's heat shield. Credit: NASA

Astronaut Piers Sellers during an STS-121 spacewalk in 2006 to demonstrate techniques on repairing the shuttle’s heat shield. Credit: NASA

Could a long mission to Mars increase your risk of heart problems back on Earth? That’s something that scientists are trying to better understand after discovering that hearts become temporarily rounder in space, at least in a study of 12 astronauts.

The finding doesn’t appear to be a big surprise for cardiovascular scientists, however, who had the astronauts examine their hearts using ultrasound machines on the International Space Station as well as before and after spaceflight. The heart gets 9.4 percent more round, similar to models developed for the project, before returning to its normal shape on Earth.

“The heart doesn’t work as hard in space, which can cause a loss of muscle mass,” stated James Thomas, 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.”

Astronauts typically spend six months on the International Space Station. One year from now, NASA’s Scott Kelly and Roscomos’¬†Mikhail Kornienko are going to launch for a one-year mission. Spending months upon months in space leads to a host of problems upon returning to Earth. Your muscles get weaker, you’re more likely to pass out, and you’re at increased risk of bone fractures, among other problems.

NASA astronaut Norm Thagard exercises aboard the Russian Mir space station in 1995. Thagard was the first American to launch into space aboard a Soyuz and spent what was then a record-breaking 115 days in space. Credit: NASA

NASA astronaut Norm Thagard exercises aboard the Russian Mir space station in 1995. Thagard was the first American to launch into space aboard a Soyuz and spent what was then a record-breaking 115 days in space. Credit: NASA

A typical person on the space station spends two hours a day exercising just to ward off the worst of the effects. The researchers added that one remedy could be to add more exercises targeting the heart. This will be particularly important for missions that last 12 to 18 months or more — such as a Mars mission.

Studying astronauts in space could provide data on Earth-bound patients facing similar problems, the researchers said. Since the models that they made for astronauts were so congruent with reality, this gives the researchers confidence that they could create similar models for patients on Earth.

Conditions that could be considered include ischemic heart disease (the most common kind of heart disease and source of heart attacks), hypertrophic cardiomyopathy (thickened heart muscle) ¬†and valvular heart disease (damage to one of the heart’s valves).

Results were presented last week at the American College of Cardiology’s annual conference. It’s not immediately clear from a press release if the study was peer-reviewed. The researchers added that more study of astronauts after returning to Earth could be a useful research direction, to see how the effects persist (if at all.)

Source: American College of Cardiology

About 

Elizabeth Howell is the senior writer at Universe Today. She also works for Space.com, Space Exploration Network, the NASA Lunar Science Institute, NASA Astrobiology Magazine and LiveScience, among others. Career highlights include watching three shuttle launches, and going on a two-week simulated Mars expedition in rural Utah. You can follow her on Twitter @howellspace or contact her at her website.

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