Leonard David's INSIDE OUTER SPACE

Canadian Space Agency astronaut David Saint-Jacques performs an ultrasound for Vascular Echo, one of three Canadian experiments in the Vascular series, which study the effects of weightlessness on astronauts’ blood vessels and hearts aboard the International Space Station.
Credits: Canadian Space Agency/NASA

Heart failure in space is the focus of new research that could influence the future of space tourists on their microgravity journeys.

This work involves a mathematical model of the heart and lung system to simulate how microgravity could affect an individual, particularly those not well-groomed for the experience.

Non-professional astronauts

The research paper – “Computational modeling of heart failure in microgravity transitions” – appears in the Frontiers in Physiology journal.

“The space tourism industry is growing due to advances in rocket technology. Privatized space travel exposes non-professional astronauts with health profiles comprising underlying conditions to microgravity,” the research paper points out, led by Stefan L. Wilson.

“Prior research has typically focused on the effects of microgravity on human physiology in healthy astronauts, and little is known how the effects of microgravity may play out in the pathophysiology of underlying medical conditions, such as heart failure,” the paper adds.

Schematic overview of the 21-compartment cardiovascular model. Reproduced from van Loon et al., 2022

Area of study

According to co-author, Lex van Loon, an assistant professor at the Australian National University and the University of Twente in the Netherlands, the unique cardiovascular challenges posed by space travel could significantly affect heart failure patients, making this an essential area of study.

“As commercial space travel becomes more accessible, individuals with various underlying health conditions—including heart failure—may soon be among those venturing beyond Earth’s atmosphere,” van Loon explains. “This raises critical questions about the impact of space travel on humans with potential underlying health problems,” he adds, with new findings “offering insights that could shape the future of space travel.”

Image credit: NASA

Notable effects

As has been noted since the dawn of human space travel, the human body undergoes significant changes when encountering microgravity.

“One of the most notable effects is the redistribution of bodily fluids, causing what is commonly known as ‘puffy face bird leg’ syndrome,” van Loon points out.

This fluid shift results in reduced venous pooling in the legs and increased venous pressure in the upper body.

On one hand, for healthy individuals, the cardiovascular system can adapt to these changes, “but for heart failure patients, the risks are substantially higher,” van Loon says.

Van Loon and fellow research colleagues observe that the demographic of commercial space travelers is shifting. Increasingly, there are older, wealthy individuals who may not be in optimal health.

The New Shepard NS-21 astronauts at apogee. Left to right: Victor Vescovo (upper left), Victor Correa Hespanha (lower left), Katya Echazarreta, Hamish Harding, Jaison Robinson, and Evan Dick. (June 4, 2022).
Image credit: Blue Origin

“Unlike professional astronauts, these space tourists typically do not undergo rigorous health screenings or physical training,” Van Loon explains. “This shift necessitates a broader consideration of health conditions, such as heart failure, diabetes, and other chronic illnesses, in space mission planning.”

Cardiac pathologies

As underscored in the research paper, this study focused on elucidating safety concerns during space tourism, specifically during entry into microgravity.

“However, longer-term space travel, such as journeys to Mars, is associated with cardiac atrophy, alterations in pulmonary volumes and perfusion, electrical abnormalities, and other cardiovascular and hemodynamic changes,” the paper observes. “Future research should explore the potential effects of extended space flight on individuals with cardiac pathologies.”

To read the full paper — “Computational modeling of heart failure in microgravity transitions” — in the Frontiers in Physiology journal, go to:

https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2024.1351985/full