Abstract
Effects of hotspring bathing on various circulatory functions in man ware studied at the Kombugawa Onsen (muriated alkaline spring), Kombu, Hokkaido.
A) Effects of the single bathing on the circulatory functions.
1) Pulse rate showed a diphasic change, namely, it increased immediately after bathing, decreased below the prebathing rate 60 minutes later and then gradually rose but did not reach the initial rate even 120 minutes later.
2) i) Systolic pressure decreased immediately to 60 minutes after bathing and then tended to return but not reached the prebathing level even 120 minutes later.
ii) Diastolic pressure showed the lowest level immediately after bathing and returned to its previous level within 90-120 minutes.
iii) Pulse pressure took the lowest value 30 minutes later and showed the prebathing value within 90-120 minutes.
iv) The higher the initial systolic pressure, the more marked was the systolic pressure reduction after bathing.
v) There was no significant change in effects on systolic pressures after bathing between 38°C bath for 20 minutes and 41°C bath for 10 minutes.
3) Arm-to-pharyngeal circulation time was shortened immediately after bathing.
4) RR interval of ECG was definitely shortened 5 minutes after bathing and gradually returned thereafter. No significant change in configuration of complexes, PQ, QT interval and QT ratio occurred.
5) Amplitudes of systolic complexes HI, IJ, JK in ballistocardiogram increased by 30% soon after bathing and decreased by 10% 15 minutes later.
L, M and N waves increased or became more definite immediately to 10 minutes after bathing in half of the cases.
6) Cardiac output slightly increased 10 to 15 minutes after bathing.
7) i) Pulse wave conduction time (the time from the beginning of Q in ECG to the beginning of upstroke in the plethysmogram) was not influenced by bathing.
ii) Crest time of plethysmogram tended to slightly shorten immediately after bathing, returned in 30 minutes and lengthened 120 minutes later.
iii) The upstroke gradient of the pulse wave markedly increased immediately after bathing and returned 120 minutes later.
iv) The amplitudes of pulse wave increased markedly soon after, then gradually reduced but was remarkedly higher even 120 minutes later.
B) Effects of the serial bathing on pulse rate and blood pressure.
1) No change in pulse rate was noticed.
2) i) Systolic pressure, diastolic pressure and pulse pressure decreased on the 2nd day and kept to a lower value during the course of bathings.
ii) The higher the prebathing blood pressure, the more marked the degree of blood pressure reduction.
iii) There was a significant correlation between the maximal systolic pressure reductions after single bathing and during serial bathings.
