How spaceflight challenges human cardiovascular health

Abstract

The harsh environmental conditions in space, particularly weightlessness and radiation exposure, can negatively affect cardiovascular function and structure. In the future, preventive cardiology will be crucial in enabling safe space travel. Indeed, future space missions destined to the Moon and from there to Mars will create new challenges to cardiovascular health while limiting medical management. Moreover, commercial spaceflight evolves rapidly such that older persons with cardiovascular risk factors will be exposed to space conditions. This review provides an overview on studies conducted in space and in terrestrial models, particularly head-down bedrest studies. These studies showed that weightlessness elicits a fluid shift towards the head, which likely predisposes to the spaceflight-associated neuro-ocular syndrome, neck vein thrombosis, and orthostatic intolerance after return to Earth. Moreover, cardiovascular unloading produces cardiopulmonary deconditioning which may be associated with cardiac atrophy. In addition to limiting physical performance, the mechanism further worsens orthostatic tolerance after return to Earth. Finally, space conditions may directly affect vascular health, however, the clinical relevance of these findings in terms of morbidity and mortality is unknown. Targeted preventive measures, which are referred to as countermeasures in aerospace medicine, and technologies to identify vascular risks early on will be required to maintain cardiovascular performance and health during future space missions.

The Effect of Submaximal Exercise on Jugular Venous Pulse Assessed by a Wearable Cervical Plethysmography System

“…In addition to cardiovascular function, the ax parameter could be also useful for the assessment of cerebral drainage. Indeed, in challenging condition such as spaceflight, showed a microG time-exposure relation, decreasing during flight permanence, followed by a normalization at return to the Earth [ 8 , 9 , 10 ]. Therefore, the use of this parameter becomes useful for monitoring the influence of exercise on cerebral venous drainage.…”

“…It was demonstrated that the reduction of cardiac output in cosmonauts during long term exposure to micro-G is associated with cognitive alterations and visual disturbances. Microgravity exposure causes the shift of fluid to the upper part of the body, inducing an increase of intracellular and interstitial fluid volume [ 9 , 10 ]…”

Beat to BEAT – Non-Invasive Investigation of Cardiac Function on the International Space Station

“…Health is key for any successful mission, and space agencies are searching for reliable, durable, versatile, and non-complex health monitoring and diagnostic solutions. In manned space flight the cardiovascular system is especially at risk [1]. To offer a possible solution for the future, the authors developed a wearable sensor system that may provide low weight and low maintenance cardio-vascular monitoring which is nevertheless comfortable and continuous.…”

Multiscale modeling in the framework of biological systems and its potential for spaceflight biology studies

“…Understanding cardiovascular risk factors and preventive cardiology will be a key component of safe long-term space travel. 49 , 50 Targeted preventive measures, or countermeasures in aerospace medicine, and identifying vascular risks early will be essential in maintaining cardiovascular performance and health during future space missions. The cardiovascular system undergoes major changes in cardiac parameters, from orthostatic intolerance, arrhythmias, and aerobic capacity to cardiac atrophy.…”

“…In addition to diminishing physical activity, this can lead to poorer orthostatic tolerance after return to Earth. 50 The space environment may directly impact vascular health; however, the clinical relevance of these findings in terms of morbidity and mortality is unclear at this point in time. Van loon and colleagues developed an open-source lumped mathematical model of the cardiopulmonary system that can simulate the short-term adaptations of crucial hemodynamic parameters to an active stand test after being exposed to microgravity.…”