Effect of high-gravity acceleration forces and anti-gravity maneuver for cardiac function in fighter pilots

Abstract Background Environmental factors such as hypoxia and gravity affect to the human cardiovascular system. It’s more important for fighter pilots who are exposed to high altitude, harsh gravitational (G) acceleration, and perform anti-G maneuvers similar to the Valsalva maneuver. Experimental studies examining how high gravitational acceleration and anti-gravity maneuver affect cardiac function are rare. Purpose This study aimed to investigate the effect on cardiac function of fighter pilots exposed to high G acceleration forces. Methods From July 2019 to June 2020, fighter pilots underwent regular health check-up and echocardiogram. Data from trainees who did not experience a flight were used for control group. Echocardiographic data included left ventricle (LV) chamber size, systolic function, and diastolic function, as well as right ventricle systolic pressure (RVSP), inferior vena cava (IVC) collapsibility, and the tricuspid annular plane systolic excursion (TAPSE) to evaluate right heart function. The multiple linear regression analysis for TAPSE was performed with total flight time as an independent continuous variable in fighter pilots. Results We enrolled 29 fighter pilots (41±10years-old; male, 100%; mean flight time 1821±1186 hours) and 16 trainees (36±17years-old; male, 100%). There was no significant difference in age, blood pressure, LVEF, RVSP, and the IVC collapsibility between fight pilots and trainees. In multivariate linear regression analysis for fighter pilots, TAPSE was affected by total flight time with positive correlation. Conclusion The experience of fighter pilots exposed to the high G acceleration forces and anti-G maneuver might be associated with right heart function change, but not associated with the prominent cardiac structural changes.