Task Cardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capacity, and Risk of Cardiac Arrhythmias (ICV-Bungo/Levine, Active) (Completed)
Last Published:  07/30/20 02:45:15 PM (Central)
Short Title: Integrated Cardiovascular Study/ICV
Responsible HRP Element: Human Health Countermeasures
Collaborating Org(s):
Human Health Countermeasures (HHC) Element
Funding Status: Completed - Task completed and produced a deliverable
Procurement Mechanism(s):
Solicited
Aims:
This comprehensive study integrates the objectives of two NRA investigations and a SMO and involves both intramural and extramural investigators.

Specific Aims:

1a:  To determine the magnitude of left and right ventricular atrophy associated with long duration space flight, and to relate this atrophy to measures of physical activity and cardiac work in-flight.  Magnetic resonance imaging (MRI) will be performed pre-and post-flight as the most accurate means of measuring cardiac mass, including sufficient repetitions to document recovery. 1b:  To determine the time course and pattern of progression of cardiac atrophy in-flight using cardiac ultrasound.


2: To determine the functional importance of cardiac atrophy for cardiac diastolic function and the regulation of stroke volume during gravitational transitions, by using innovative, non-invasive imaging techniques to measure the dynamic component of diastole including: a)  tissue Doppler and strain rate imaging to quantify ventricular wall motion with high temporal resolution; b) color Doppler M-mode echocardiography to quantify intraventricular pressure gradients and assess the magnitude of diastolic suction; and c) magnetic resonance imaging with myocardial tagging to quantify the rate of untwisting.


3:  To identify changes in ventricular conduction, depolarization, and repolarization during and after long duration spaceflight, and relate these to changes in cardiac mass and morphology (presence of fibrosis and/or fat accumulation). Although the direct assessment of arrhythmia risk in otherwise healthy subjects is imprecise, the goal of this aim is to combine the best currently available non-invasive tests of arrhythmia risk with high negative predictive value to demonstrate convincingly the absence of risk for life threaten arrhythmias.


Data will be obtained twice pre-flight, at 2 weeks, 4 weeks, and every 1-2 months during flight, and 3 times post-flight.  In-flight testing will require holter monitoring, 2-d echocardiography, and ambulatory blood pressure monitoring.  After completion of this study, the clinical expression of cardiac atrophy during long duration spaceflight will be defined clearly, and its significance for cardiac systolic and diastolic function at rest and during gravitational transitions will be elucidated.  In addition, preliminary information will be obtained regarding ventricular conduction and repolarization that will provide either strong clinical reassurance, or pathophysiologic insight into the risk for cardiac arrhythmias.
Mappings
RiskRisk of Spaceflight Induced Cardiovascular Disease
You are here!TaskCardiac Atrophy and Diastolic Dysfunction During and After Long Duration Spaceflight: Functional Consequences for Orthostatic Intolerance, Exercise Capacity, and Risk of Cardiac Arrhythmias (ICV-Bungo/Levine, Active)