Effect of passive heat exposure on cardiac autonomic function in healthy children

摘要

Purpose The aim of this study was to examine the effect of passive heat stress on heart rate variability parameters in healthy children. Method Fifteen children (9.3?±?1.6?years) of both sexes (eight male) participated in two randomized experimental conditions separated by 5–12?days. Children were seated for 2?h in an environmental chamber for two sessions: neutral (22.4?±?0.1?°C, 40.4?±?6.5% RH) and hot (34.9?±?0.3?°C, 36.6?±?6.2% RH) conditions. Electrocardiogram, mean skin temperature, tympanic temperature, and blood pressure were recorded. Five min epochs were averaged for analysis of cardiac autonomic function over the 2-h protocol. Result Mean skin and tympanic temperatures and heart rate increased during the hot condition (all p ? ?0.05), except for LF/HF ratio which decreased during the neutral condition ( p ?