Haemodynamic changes in man during immersion in water at different temperatures

Abstract

1. Stroke volume and cardiac output were measured using the Doppler ultrasound technique in 16 normal subjects immersed to the neck in water at 33 degrees C, 35 degrees C, 37 degrees C and 39 degrees C. A standard aortic diameter was assumed and results were expressed as percentage changes from pre-immersion resting values. 2. Cardiac output rose progressively at higher temperatures, increasing by 30% at 33 degrees C and by 121% at 39 degrees C. At thermoneutral temperatures (33 degrees C and 35 degrees C) this was achieved by an increase in stroke volume of 50% despite a significant decrease in heart rate. There was a further rise in stroke volume and pulse rate at higher temperatures and a mean tachycardia of 109 +/- 4 beats/min was noted at 39 degrees C. Calculated peripheral resistance reduced progressively with increasing temperature of immersion. 3. This non-invasive and simple technique may provide a non-exercise-related cardiovascular stress test to study cardiovascular responses in a variety of pathophysiological states.

Is hydrotherapy cost-effective? A randomised controlled trial of combined hydrotherapy programmes compared with physiotherapy land techniques in children with juvenile idiopathic arthritis

“…Advantageous hydrodynamic and physiological effects of immersion and exercise in water allow greater freedom of movement and more effective rehabilitation. 24,33,34,45,46,54,55,94,95 Improvement in disease would presumably lead to improved HRQoL and increased QALYs gained, which would offset high fixed costs. However, the gains in disease improvement during intervention were insufficient to affect HRQoL meaningfully (based on results from the EQ-5D) and have QALYs gained in either group, and although more patients improved in the land than the combined group, the difference was neither clinically or statistically significant.…”

“…Immersion to the neck in heated water results in a number of physiological responses triggered by an increase in hydrostatic pressure. An increase in distal venous pressure leads to central hypovolaemia, with subsequent cardiovascular responses resulting in increases in cardiac output and stroke volume, 33,34 which lead to inhibition of the sympathetic nervous system, which in turn reduces vagal vasomotor tone, inducing muscle relaxation and central sensitisation to pain. 35,36 Furthermore, superficial heating of the skin and underlying structures leads to a reduction in striated muscle tone, cutaneous vasodilatation and a reduction in peripheral vascular resistance.…”

Cardiovascular responses in rest, exercise, and recovery phases in water immersion

“…However, because the heat load of the hot water induces an increase in HR, the increase in CO is markedly greater than that obtained in other water temperature immersions 13,15) . In hot water immersion, cutaneous blood flow increases due to skin vasodilatation, which is related to body temperature regulation.…”

New evidence on mechanisms of action of spa therapy in rheumatic diseases

“…Immersion to the suprasternal notch in mineral water (35°C) results in a cascade of reactions including increased diuresis, natriuresis, and cardiac output (Epstein, 1992;O'Hare et al, 1985;Weston et al, 1987). The basis of these physiological effects is considered to be the hydrostatic pressure, which forces approximately 700 ml from the lower extremities to the central compartment.…”