The Effect of Posture on the Excretion of Water and Sodium by Patients with Congestive Heart Failure

Four patients with congestive heart failure were studied in the sitting and the recumbent positions. After hypotonic loading maximal diuresis set in at six hours, as compared with three hours in the normal subjects. Heart failure patients never excreted more than 50 per cent of water intake in either position. Likewise, these patients never equalled sodium intake with urinary excretion of sodium. Sodium excretion in the two positions was approximately the same. Increase in venous pressure, lengthening of circulation time, decline of vital capacity, and decline of serum sodium concentration were noted after each investigation period. These results are interpreted as indicating that the previously postulated intracranial volume regulating center is either inactive or over-powered by a more powerful mechanism in the patient with congestive heart failure.