413 CARDIOVASCULAR CHANGES MICROGRAVITY-RELEATED: SYSTEMATIC REVIEW OF THE LITERATURE

Abstract

Abstract Introduction Microgravity-relevant space is characterized by different environmental conditions than terrestrial space, including microgravity, vacuum/hypovaria, acceleration, extreme temperature, ionizing radiation, and confinement/isolation. The space environment induces biomechanical and cardiovascular stress during both takeoff and landing, exposing astronauts to the development of cardiovascular disease (CVD). This literature review focuses on cardiovascular changes that can be traced to an aerospace mission. (Baran, R., et All. 2021). Materials and Methods A systematic literature review was conducted to assess the cardiovascular changes that occur on the human body in microgravity. The search was performed using PUBMED as the database. The inclusion criteria established, for an article to be used, was the relevance of the topic. The choice of articles that were subsequently included in the study was based on predetermined questions and inclusion and exclusion criteria in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses). The quality of the study was assessed by two reviewers and then discussed with a third reviewer using the DIXONWOOD checklist. Results and Discussion Baran, R. et all studied cardiovascular changes during spaceflight in vivo and related molecular changes in vitro that, were outside the scope of pre-flight cardiovascular disease. These changes are related to several factors, including the absence of orthostatic pressure, and reduced blood pressure, which results in a depletion of cardiac workload, sometimes leading to cardiac atrophy, i.e., reduced ventricular size in cosmonauts following a mission. In the face of these, the scientific community is investigating through pre- and post-flight simulation tests the adaptation and prevention of the cardiovascular system. An exposure to microgravity greater than 6 months cascades numerous physiological adaptations. Indeed, there is a shift in body fluids, arrhythmias, and an increase in systolic output (35-46%) and cardiac output (18-41%). Despite these increases, astronauts may enter a hypovolemic state and cardiogenic shock (10-15% decrease in volaemia). (Baran, R., et All. 2021). In addition to this, prolonged stay in Space, exposes, the cosmonaut to syncopal events of cardiogenic origin in the re-entry and post-landing phase. (Meck, J. V., et All. 2001). Conclusions Exposure to microgravity conditions results in significant changes in cardiovascular function. Further clinical studies in larger samples are, however, needed to understand and prevent microgravity exposure-related CVD. For future applications and theoretical-practical investigations, there also emerges the need, in view of increasingly longer and riskier missions̀ health teleconsultations, for the presence of the health care team on board the shuttle or at the bases alreadỳ present in Earth orbit.