The hyperbaric effect to heart rate and short-term heart rate variability on young pilots

Abstract

Objective To investigate the effect of high pressure change to heart rate (HR) and short-term heart rate variability (HRV) on young pilots. Methods HR, standard deviation of the NN interval (SDNN), root mean square of the squared differences of successive NN intervals (RMSSD), and percentage of the difference of successive NN interval >50 ms (PNN50) in 5 minitues of 30 young pilots were recorded by dynamic electrocardiogram before, in and at constant pressurization, as well as in decompression and after decompression in a hyperbaric chamber. Data were statistically analyzed. Results Pressurization might cause HR decreased. HR varied from 76.56±12.33 bpm before pressurization, 67.25±10.21 bpm during onset of pressurization, to 65.06 ±7.02 bpm at peak. With the return to normal atmospheric pressure, HR increasedly recovered but never to the level before pressurization. Such HRV parameters as SDNN that mainly reflected the combined sympathetic and vagal tone, and RMSSD and PNNs0 that indicted vagal tone, were varied with atmospheric pressure. Conclusions Change of atmospheric pressure may significantly affect young pilots' HR and short-term HRV, and this would be cared in pilot selection and training. Key words: Atmospheric pressure; Electrocardiography, ambulatory; Heart rate