LSDA - Experiment

NASA Home Research Search Database Tissue Request Just For Fun Reading Room Medical

Life Sciences Data Archive

@ Johnson Space Center, Houston, Texas

EXPERIMENT INFORMATION

Cardiac Atrophy and Diastolic Dysfunction During and After Long-Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capacity, and Risk of Cardiac Arrhythmias (99-E377)

Principal Investigators

+ Bungo, Michael W.
+ Levine, Benjamin D.

Bioastronautics Roadmap

+ Cardiovascular Alterations

Species Studied

Homo sapiens (Human)

Experiment Description

OBJECTIVES:
Cardiac atrophy appears to develop during space flight or during ground-based analogues, leading to diastolic dysfunction and orthostatic hypotension. Such atrophy may also be a potential mechanism for the cardiac arrhythmias recently identified in some crewmembers after long-duration exposure to microgravity aboard the Mir space station. Recent work by the investigators of this flight experiment has suggested that cardiac atrophy may be progressive, without a clear plateau over at least 12 weeks of bed rest, and thus may be a significant limiting factor for extended duration space missions. The purpose of this experiment is to quantify the extent and time course of cardiac atrophy and identify its mechanisms. The functional consequences of this atrophy will also be determined for cardiac filling dynamics, orthostatic tolerance at 1G and fractional G (Mars and moon) conditions, exercise tolerance, and arrhythmia susceptibility both in space on the International Space Station, and following return to earth.

The main objectives of this experiment are:

• To determine the magnitude of left and right ventricular atrophy associated with long-duration space flight (via pre- and postflight MRI's), to relate this atrophy to measures of physical activity and cardiac work in flight, and to determine the time course and pattern of progression of cardiac atrophy in flight (using cardiac ultrasound)

• To determine the functional importance of cardiac atrophy for orthostatic tolerance and the regulation of stroke volume.

• To identify changes in ventricular conduction and repolarization during and after long-duration space flight.

++ -- Description Continues

APPROACH:
Between L-75 and L-60 days, each subject will perform an Exercise Echocardiogram (Echo) and Electrocardiogram (ECG) session, which will include echocardiography measurements before and after submaximal exercise and an ECG recording throughout the session. Holter, ambulatory blood pressure (BP), and activity monitors will be worn for the 24 hours following this session. A Cardiac Magnetic Resonance Image (MRI) and Cardiac Function test (including optional measurements of central venous pressure (CVP), via a peripherally inserted central catheter, and cardiac output during a graded tilt test) will be performed in the L-75 to L-60 timeframe. Between L-21 and L-7 days, a Resting Echo/ECG session followed by 24 hours of Holter, ambulatory BP, and activity monitoring will be performed. Postflight, the Cardiac Function test (without direct CVP measurements) and 24-hour monitoring will be performed on landing day and Exercise Echo/ECG (R+4 and R+14), Resting Echo/ECG (R+7), and Cardiac MRI (R+3 and R+22) sessions are planned. Resting echocardiograms using the Human Research Facility (HRF) Ultrasound with ECG recording will be performed on flight days 14, 30, 135, and R+15 using real-time remote guidance. On flight day 75, an exercise Echo session will be performed with Echo measurements before and after exercise. QT Dispersion and signal averaged ECG measurements will also be recorded at this session. Both the Resting and Exercise Echo sessions will be followed by 24 hours of ambulatory BP/Holter/Activity monitoring. Following the doffing of the ambulatory devices, data from all experiment hardware will be downloaded to the HRF personal computer (PC) or Workstation and downlinked to the ground. In-flight exercise and medication logs will be obtained through data sharing.

RESULTS:
This investigation is currently in operation. Results will be available upon completion of the experiment.

Keywords :
• Arrhythmia
• Cardiovascular physiology
• Cardiovascular system
• Exercise tolerance
• Orthostatic hypotension

++ -- KeyWords Continue

• Ventricular function

Photo Gallery

+ View digital images

Data Information

Data Preservation Status

Preservation in progress

Data Availability

Experiment is described. Some data may be on the Web site, and additional data may be available at a later date.

Measurements

• Blood pressure
• Central venous pressure
• Echocardiogram
• Electrocardiogram
• Heart rate

++ -- Measurements Continue

• Respiratory rate

Space Flight Missions

Mission

Launch/Start Date Landing/End Date Duration

+ Human Research Facility on Expedition 20

05/27/2009 10/12/2009 138 days

+ Human Research Facility on Expedition 21

09/30/2009 11/23/2009 54 days

+ Human Research Facility on Expedition 22

11/30/2009 05/15/2010 In Progress

Other Information About This Experiment

Co-Investigators

+ Hamilton, Douglas
+ Johnston, Smith
+ Platts, Steven

Managing NASA Center

Johnson Space Center (JSC)

Responsible NASA Representative

Johnson Space Center LSDA Office
Project Manager: Mary A. Fitts

Institutional Support

National Aeronautics and Space Administration (NASA)

Experiment Types

+ Non-exercise Physiological Countermeasure (NxPCM) Project
+ International Space Station (ISS)

Alternate Experiment Names

377
Cardiac
E046
E377
ICV
Integrated Cardio

Research Area

Cardiovascular physiology

Life Sciences Data Archive-feedback2

? NASA

Last Updated: 11/06/2009 - v8.d

Webmaster: Abul A. Chowdhury

Curators: Afzal Ahmed , Jacque Havelka

NASA Official: Mary A. Fitts

Baselined: 7/15/2004

Budgets, Strategic Plans, and Accountability Reports ExpectMore.gov Information-Dissemination Policies and Inventories Freedom of Information Act President's Management Agenda Privacy Policy & Important Notices Inspector General Hotline Contact LSDA / Feedback Site Map Related Links Johnson Space Center USA.gov