Influence of the professional activity of pilots on the adaptive pattern of hemodynamic reactions to the tilt test

Abstract

A comparative study of the blood circulation’s response to the tilt test was performed in three groups of healthy subjects: AF pilots (n = 72), engine drivers (n = 44), and students at the Military Institute of Radio Electronics (n = 32). In all the groups, adequate adaptive responses to the test were recorded under eukinetic hemodynamics where steady cardiac output and blood pressure values combined with an increase of the heart rate by 10–12%. Hypokinetic hemodynamics caused a 20% increase in cardiac output during the initial 5 min of orthostasis in pilots versus an 8–12% increase in the others. Hyperkinetic hemodynamics were responsible for the increase in the cardiac output in pilots but not in the other groups. Parasympathetic system activation was peculiar of hypokinetic hemodynamics, while sympathetic system activation was associated with hyperkinetic hemodynamics. These results suggest a larger body functional reserve in pilots compared to other subjects as a side effect of their profession.