Researchers are already planning what might happen to a space tourist if they have a heart problem. 

Billionaires aspiring to space tourism should evaluate their heart health before embarking on their journey, Australian researchers have advised. 

A team from the Australian National University and the University of Twente in the Netherlands has highlighted the increased risks faced by individuals with heart conditions when exposed to the microgravity environment of space.

Most existing research on the physiological impacts of space travel focuses on fit, healthy astronauts. 

However, the rise in commercial space travel means that wealthier but potentially less healthy individuals are also preparing to venture beyond Earth. 

Dr Lex van Loon, an assistant professor at both the Australian National University and the University of Twente, along with his team, used computational modelling to simulate the effects of microgravity on humans with two types of heart failure.

Microgravity, the condition in which objects appear to be weightless, exerts unique pressures on the human body. 

For those with heart conditions, these pressures can be particularly dangerous. 

The research team's models indicate that individuals with heart failure are at an increased risk of pulmonary oedema - a condition where fluid accumulates in the lungs, making breathing difficult - when exposed to microgravity. This fluid shift occurs because microgravity causes bodily fluids to redistribute, often leading to increased venous pressure in the upper body.

Dr van Loon's research, published in the journal Frontiers in Physiology, delves into these risks by using a mathematical model of the cardiovascular system. 

By adjusting the parameters of this model, the team was able to predict the responses of heart failure patients during space travel with a high degree of accuracy.

“Our simulations revealed that entry into microgravity increases cardiac output in all individuals. However, for heart failure patients, this increase in cardiac output is accompanied by a dangerous rise in left atrial pressure, which can lead to pulmonary oedema,” Dr van Loon says.

The demographic of space travellers is likely to include many older, wealthier individuals who may not be in peak physical condition. 

Unlike professional astronauts, these individuals do not undergo the same rigorous health screenings and physical training. 

This shift necessitates a broader understanding of how chronic illnesses like heart failure, diabetes, and other conditions might interact with the unique environment of space.

Heart failure affects over 100 million people globally and can manifest in two primary forms: one where the heart cannot pump blood effectively, and another where the heart cannot relax and fill properly. 

Each type presents unique challenges in a microgravity environment, highlighting the need for specific research and tailored countermeasures.

The study suggests comprehensive health screenings and personalised medical plans will be needed for space tourists. 

As the accessibility of commercial space travel increases, ensuring the safety of all passengers, especially those with preexisting conditions, becomes paramount. 

The experts say further research is needed to understand the long-term effects of space travel on cardiovascular health, including the cumulative impact of comorbidities.

A promising avenue for enhancing safety in space travel is the development of human digital twins - detailed virtual models of an individual's physiological systems. 

By creating these digital replicas, it is possible to simulate various scenarios and predict how different conditions, such as microgravity, might affect an individual's health. 

For heart failure patients, a digital twin could simulate how their specific condition would respond to space travel stresses, helping to identify the most effective pre-flight preparations and in-flight interventions.