Cardiovascular responses to ice-cold showers

Abstract

A shower of ice-cold water (0@#X2013;2.5 C) over the chest caused large increases in systolic and diastolic arterial pressures, pulse pressure, and pulse rate in normal subjects. Cardiac output rose by 59 and 100% in the two subjects in whom it was measured. The changes in pressure were considerably larger than those caused by a cold pressor test or by anxiety. The changes appear to be due to sympathetic nervous reflexes to the heart and blood vessels rather than release of adrenal catecholamines, as plasma epinephrine did not increase and plasma norepinephrine rose only by 0.32 @#X00B5;g/liter. Hyperventilation and evidence of peripheral venoconstriction occurred during the showers, but neither voluntary hyperventilation nor increased venous return from a change in posture produced the changes in blood pressure seen during shower arterial blood pressure; cardiac output; catecholamines; sympathetic nervous reflexes; hyperventilation; peripheral venoconstriction Submitted on March 10, 1964