Written with Dr. James Thomas
Director of Cardiovascular Imaging Section, Tomsich Family Department of Cardiovascular Medicine
Strange things happen to astronauts after long periods of time in space, as zero gravity tends to play havoc on cardiac function and resultant blood flow.
- Their heads get bigger.
- Their legs get thinner.
- Their blood pressure falls.
By the time they get back to earth, they often barely can sit up without fainting. These problems are serious, and unless solved, can ground any future plans for long-distance space travel to places like Mars.
In order to keep the international space effort afloat, the Miller Family Heart & Vascular Institute and the National Aeronautics and Space Administration (NASA) are working together on a new research project. They’re interested in what happens to the heart in space and how to keep it working properly once back on Earth.
Dr. Jim Thomas, Director of the Cardiovascular Imaging Section at the Miller Family Heart and Vascular Institute, and son at shuttle launch
Astronauts who’ve been in space for long periods of time experience cardiovascular de-conditioning. "They return to Earth weakened," Director of Cardiovascular Imaging at the Miller Family Heart & Vascular Institute James Thomas said. "They have low blood pressures, less blood volume and loss of tone to their blood vessels."
It is not yet known why the weakening occurs or if the heart itself is weakened. We do know, however, that pumping blood is easy in space and gravity can be linked as a guilty conspirator. "The heart begins to think it’s on vacation, and the blood vessels get less firm," Thomas said. Without gravity, more blood is able to circulate to the head with less to the legs. This causes the head to swell slightly and the legs to shrink.
Thus, the importance of understanding the long-term effects of weightlessness has become more urgent than ever as the International Space Station has been in orbit some 900 days.
Space Shuttle Discovery launch, March 8, 2001.
On March 8, 2001, Shuttle Discovery and its crew brought along an echocardiograph machine to be placed aboard the ISS. This machine takes pictures of the heart using sound waves and is now part of the US Lab Module’s Human Research Facility (HRF), where it is housed in conjunction with other research machines. Administrator of NASA Dan Goldin said the study is part of an overall push to find new, noninvasive diagnostic and treatment alternatives. "Astronauts are some of the healthiest people in the world, but you can’t always have a doctor on board in case something goes wrong," Goldin said.
Echocardiograph machine aboard International Space Station's Destiny Research Laboratory
TheMiller Family Heart & Vascular Institute has been awarded a $4 million grant to administer the use of echocardiography on board the space station. With this grant, the Miller Family Heart & Vascular Institute plans to:
- Digitize its Echocardiology Lab,
- Find new ways to compress information-rich echocardiograms to fit the narrow space-to-earth data channel,
- Develop experimental protocols to examine astronauts as they work aboard the station and
- Develop new ways to look at the heart, including 3D echocardiography.
Thomas said this research will allow physicians to view an astronaut’s heart functioning in space, make diagnoses and prescribe a course of action. "In addition, all this new imaging technology will help us better study the function of the heart and detect unseen leakages through heart valves and subtle abnormalities that can lead to congestive heart failure," Thomas said. "Three-dimensional echocardiography soon will be the norm, and thanks to the cooperative agreement with NASA, we’ll be at the leading edge of it."
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