The Effect of Long-term Microgravity Exposure on Cardiac Autonomic Function by Analyzing 24-hours Electrocardiogram (Biological Rhythms) - 07.15.14
ISS Science for Everyone
Science Objectives for Everyone The Effect of Long-term Microgravity Exposure on Cardiac Autonomic Function by Analyzing 24-hours Electrocardiogram (Biological Rhythms) examines the effect of long-term microgravity exposure on cardiac autonomic function by analyzing 24-hour electrocardiogram of long-duration ISS crewmembers.
Science Results for Everyone
Human hearts ‘heart’ a 24-hour day. Scientists study the effect of long-term microgravity exposure on cardiac function by analyzing 24-hour electrocardiograms (ECG) of space station crew members. Data from two ECG collection periods show that intervals between average main or large heart pulse, known as R-R intervals, remained almost within the 24-hour or circadian range. The data on circadian rhythm on R-R intervals in lengthy exposure to microgravity are undergoing analysis to help astronauts recover normal daily rhythms on future prolonged space travel. Any technology that addresses biological rhythm disruption during spaceflight could also promote better health for the general public.
Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)
ISS Expedition Duration
March 2009 - May 2012
Previous ISS Missions
Biological Rhythms began during ISS Expedition 19/20.
- It has been demonstrated that space flight induces adverse consequences such as cardiovascular deconditioning and sleep disturbance which may be accompanied by disruption in circadian rhythms.
- As those consequences are closely related to autonomic function, cardiac autonomic function may be changed during long- term space flight.
- The objective of this study is to examine the effect of long-term microgravity exposure on cardiac autonomic function by monitoring pre; in; and post-flight 24-hours electrocardiogram.
- The results will be analyzed for improving crew health care technology in long-duration space flight.
As cardiovascular deconditioning and sleep disturbance are major adverse consequences during space flight, those problems can be seen on the earth in the people who are less fit and/or engaged in shift work. The results of this study may contribute to understanding the mechanisms of those consequences and be beneficial to manage those problems.
Two Data collection periods of ECG readings using the Digital Holter ECG aboard the ISS were conducted to provide trends for long-duration, microgravity exposure. The average main (large heart pulse) RR intervals periods, which were involved in 24 hours were kept almost within circadian range. The circadian rhythm contained in RR intervals was significantly stronger in the latter period than that in early and middle period. The study of circadian rhythm on RR intervals in a microgravity, long-duration environment will be analyzed to assist astronauts in the recovery of normal circadian rhythms in a prolonged space stay in the future.
JAXA Digital Holter ECG Image. Image provided courtesy of JAXA.
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