Assessing the cardiac function from micro-gravity to hyper-gravity conditions through a validated multiscale...

Area of Science:

• Cardiovascular physiology
• Space medicine
• Computational modeling

Background:

• Altered gravity (microgravity and hypergravity) causes significant cardiovascular changes, including fluid shifts and orthostatic hypotension.
• Understanding cardiac function under these extreme conditions is challenging due to experimental limitations.

Purpose of the Study:

• To develop and validate a multiscale cardiovascular model (0D-1D) for investigating acute cardiac responses to gravity changes.
• To analyze cardiac hemodynamics from 0g to 3g, focusing on differences between left and right heart function.

Main Methods:

• A 0D-1D multiscale cardiovascular model integrating arterial, coronary, and peripheral circulations was developed.
• The model incorporates short-term regulatory mechanisms and accounts for gravity and posture variations.
• Model validation was performed using published data for central hemodynamic parameters like heart rate and mean arterial pressure.

Main Results:

• The model accurately predicts central hemodynamic parameters across a range of gravitational forces (0g to 3g).
• Microgravity (0g) demonstrated improved cardiac efficiency and performance.
• Hypergravity (3g) showed reduced cardiac efficiency and impaired energy supply/demand balance at both cardiac and coronary levels.

Conclusions:

• The validated computational model provides insights into cardiac function under altered gravity, complementing experimental data.
• This approach is valuable for understanding space medicine challenges and the physiological effects of extreme environments.
• The study highlights distinct left and right heart responses and identifies critical energy balance issues in hypergravity.