Effects of Spaceflight on Cardiovascular Physiology and HealthShen, Michael, MD*; Frishman, William H., MD†Cardiology in Review: May/June 2019 - Volume 27 - Issue 3 - p 122–126 doi: 10.1097/CRD.0000000000000236 Review Articles Buy Abstract Author InformationAuthors Article MetricsMetrics During spaceflight, the human cardiovascular system undergoes major changes primarily related to the effects of decreased gravitational force, or microgravity, on the human body. These changes present challenges to human adaptation and operation in space. This article reviews the knowledge gained in human experiments in the past half century of spaceflight, and summarizes our knowledge on the effects of short- and long-duration microgravity exposure on cardiovascular physiology and functioning, including fluid redistribution, autonomic reflexes, cardiac parameters, orthostatic intolerance, arrhythmias, aerobic capacity, and cardiac atrophy. This review also discusses current countermeasures for risk reduction during spaceflight, as well as future directions in cardiovascular research in space. From the *New York University-Primary Care Internal Medicine Program, New York, NY †Department of Medicine, New York Medical College/Westchester Medical Center, Valhalla, NY. Disclosure: The authors have no conflicts of interest to report. Correspondence: William H. Frishman, MD, Department of Medicine, New York Medical College, 40 Sunshine Cottage Road, Valhalla, NY 10595. E-mail: William_Frishman@nymc.edu. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.