NASA is using the Philips iE33 echocardiography system and QLAB Quantification software to evaluate the effects of space flight on the hearts of Space Shuttle astronauts.

The system will be used, in the near future, for astronauts on the International Space Station, too. Of interest to NASA researchers is the loss of heart mass brought on by space flight.

Astronauts commonly are thought to lose heart mass during prolonged flight. Two-dimensional echocardiography measurements reveal a 5 percent decrease, which usually returns within three days of being back on Earth. Researchers are interested in learning the cause of these changes. Possible explanations include heart atrophy caused by weightlessness, dehydration from space travel or error caused by the geometric assumptions used in two-dimensional echo.

The new technology being used captures a full-volume image of the beating heart in less than a minute and allows physicians to examine the heart as if they were holding it in their hands. It also allows the researchers to make accurate measurements of heart mass, ejection fraction, blood flow, strain rate and cardiac wall motion pre- and post-flight.

“Live 3D Echo allows us to quickly grab all the image data we need to do a full examination of the heart anatomy and function and send the astronauts on their way. Following the image acquisition, we use off-line analysis software to do several measurements that help us evaluate changes after space travel,” said said David S. Martin of Wyle Laboratories, Inc., ultrasound lead for the NASA Cardiovascular Laboratory at the Johnson Space Center in Houston, Texas.

The use of this heart imaging and measurement technology will be part of ongoing research at the NASA Cardiovascular Laboratory. It will also complement the imaging done by a modified Philips HDI 5000 ultrasound system that was installed in the International Space Station’s Human Research Facility in 2001.

“These new ultrasound technologies help us efficiently conduct sophisticated cardiac research of astronauts and the effects of microgravity,” said Martin.