NASA astronaut Dan Burbank, Expedition 30 commander, prepares to use the Integrated Cardiovascular Resting Echo Scan on a crew member (out of frame) at the Human Research Facility rack in the Columbus laboratory of the International Space Station. The Integrated Cardiovascular experiment investigates ventricular atrophy associated with long-duration space flight, relates this type of atrophy to measures of physical activity and cardiac work inflight, and determines the time course and pattern of the progression of cardiac atrophy inflight using cardiac ultrasound. This investigation also determines the functional importance of cardiac atrophy for cardiac diastolic function and the regulation of stroke volume (volume of blood pumped by the heart in one contraction) during gravitational transitions, as well as identifies changes in ventricular conduction, depolarization and repolarization during and after long-duration space flight, and relates these factors to changes in heart mass and morphology (shape and form).