Echocardiographic Assessment of Cardiovascular Changes in Long Term Space Flight
Echocardiographic Assessment of Cardiovascular Changes in Long Term Space Flight
The National Space Biomedical Research Institute is interested in learning more about heart
 function in space. One potential problem with long duration, manned space flight is muscle
 loss- including loss of heart muscle. One goal of our research is to help identify why this
 muscle loss occurs. We are interested in patients undergoing aortic valve surgery because
 this procedure is performed to correct a problem with the valve that may also change heart
 function. This change in heart function may provide information that is useful in
 understanding and potentially preventing the loss of cardiac muscle in space.

 Three patient groups will be studied, patients having surgery for aortic regurgitation,
 aortic stenosis, and coronary bypass. We are planing to perform this study on 30 patients, 10
 in each group.

 The aim of this study is to continue our ongoing study of the magnitude and predictors of the
 changes in size of the left ventricle following acute volume and pressure unloading as a
 ground-based analog for manned space flight.
Among the most serious of the risks identified by NASA in the area of cardiovascular
 alterations are serious dysrhythmias and the development of orthostatic intolerance.
 Prolonged exposure to microgravity may lead to a reduction in cardiac performance,
 particularly during times of stress and that undiagnosed cardiovascular disease may manifest
 during long missions. The PI and colleagues have worked closely with NASA and NSBRI over the
 last six years to optimize use of ultrasound in the space program as an investigative
 modality, addressing fundamental cardiovascular problems in need of countermeasures
 development. We propose the following specific aim:

 To continue our ongoing study of the magnitude and predictors of LV mass regression following
 acute volume and pressure unloading as a ground-based analog for manned spaceflight. This
 work will continue to focus on patients undergoing aortic valve surgery, but exploit recent
 knowledge of the roles of cytokines and integrins involved in cardiac hypertrophy and
 regression as well as emerging technologies such as gene chip analysis.

 This work will be closely focused on risks and critical questions identified by the
 Cardiovascular Alterations Team as described in the Bioastronautics Critical Path Road Map
 Baseline Document. If successful, this project will enhance assessment of cardiac function
 during long duration missions and potentially suggest cytokine promoters or signal
 transduction pathways that could be targeted for cardiac atrophy countermeasures. In
 addition, we will continue to provide the facilities of our Core laboratory for access by
 investigators throughout the NASA and NSBRI programs in need of assistance in acquiring or
 analyzing ultrasonic data.
Inclusion Criteria:

 -  > 18 years of age

 -  Isolated severe aortic stenosis

 -  Preserved left ventricular function

 -  CABG patients will have normal LV function and mass