Abstract 18672: Effects of Prolonged Space Flight on Cardiac Structure and Function
Background: “Cardiovascular deconditioning” induced by bed rest, a model for spaceflight, causes cardiac atrophy of ~1%/wk in men and women. Data from small numbers of astronauts NOT performing any exercise countermeasures suggest the rate of atrophy for spaceflight may be even greater. However, cardiac morphology has not been assessed using high resolution techniques before and after prolonged space flight in the International Space Station (ISS) era.
Methods: Cardiac magnetic resonance imaging (MRI) to assess left and right ventricular volumes and masses, and fibrosis by late gadolinium enhancement was performed within 2 months before and 3 days after 4-6 months in space aboard the ISS on 13 astronauts.
Results: Eight men and 5 women (mean age 49.5 years) astronauts participated (mean ISS duration 153 days). All performed regular and intensive combined endurance and strength training countermeasures inflight, and most did so at a higher intensity than they did pre-flight. No significant differences in left ventricular or right ventricular end-diastolic and -systolic volumes were observed (Table). Both right and left ventricular mass was preserved, and supine stroke volume was maintained. No evidence of myocardial fibrosis was seen in 11 astronauts who had late gadolinium enhancement performed before and after space flight.
Conclusions: No deleterious effects of prolonged space flight were seen on cardiac structure and function. These results suggest that an appropriate astronaut exercise regimen may counteract the effects of “cardiovascular deconditioning” during prolonged space flight up to 6 months duration.
- © 2013 by American Heart Association, Inc.