One Giant Step For Better Heart Research?
By AVERY JOHNSON
Researchers in the midst of a several years' study of how astronauts' hearts react during long space voyages reported initial findings that they say could help improve cardiac care on Earth.
They found that astronauts benefitted from certain types of exercise, something that could help patients with heart failure or abnormal heartbeats, or those who are bedridden after surgery, a stroke, or during pregnancy, whose hearts atrophy much like an astronaut's in space.
Heart muscles don't have to work as hard to circulate blood in space because gravity doesn't exert the same force. Astronauts returning from missions frequently feel lightheaded and sometimes pass out. After weeks or months in space, the heart appears to shrink, cardiologists say, blood volumes decrease, and the astronaut can experience hypotension, or abnormally low blood pressure.
The research is in its early stages, but some of it offers fresh interventions for heart patients. Benjamin Levine, one of the leaders of the NASA project, is studying astronauts exercising in space to help patients with what he calls "Grinch Syndrome," characterized by low blood pressure and the inability to stand up without losing consciousness. (The name refers to how it causes the heart to be two sizes too small like that of the Dr. Seuss character.) Dr. Levine found that seated exercise, such as using a rowing machine, can aid those patients.
The cardiologists presented the research from the NASA-funded project last week at a symposium held every other year called "Humans in Space," and earlier this month at the annual meeting of the American College of Cardiology.
"Cardiovascular research in space gives us the unique opportunity to study the effect of gravity on the heart and has led to novel understandings and therapies," said Dr. Levine, a cardiologist at University of Texas Southwestern Medical Center.
Twelve astronauts are expected to undergo detailed ultrasounds while in space and MRIs before and after flight for half a year. The project has been collecting data for two years and so far five astronauts have completed the testing. In addition to changes in blood volumes and heart size, researchers are also investigating reports of heart palpitations, known as arrhythmias, in space. To Full Article...