1999 年 4 巻 3 号 p. 133-140
The present study was conducted to investigate the cardiovascular and autonomic responses caused by bathing with different three temperatures (i.e., 29, 35 and 40℃) in six healthy male volunteers under the continuous ECG monitoring, serial echocardiographic examination, blood pressure measurement and venous blood sampling. As a result, hydraulic effects of bathing caused an increase in the left ventricular end-diastolic volume probably based on augmented venous return. With respect to the thermal effects, high temperature (i.e., 40℃) bathing caused increased cardiac workload (i.e., increased heart rate and double product), vasodilatation (i.e., decreased total peripheral vascular resistance) and sympathetic acceleration evaluated by plasma catecholamine and spectral analysis of heat rate variability. Various temperature-dependent neurohumoral factors are considered to underlie the cardiovascular as well as autonomic responses. In conclusion, optimal bathing temperature has to be determined to prevent the sudden cardiac death in bathing.