Electrolyte disturbances in congestive heart failure.

Abstract

ras 44.2 mg. per minute. The mean filtration fraction, which is an expression of the glomerular filtration in relation to the renal plasma flow (G:F./R.P.F.) showed a definite increase from the normal of 17.4 per cent to 40.5 per cent in decompensated patients. This increase in the filtration fraction has been explained in the current concept as being a result of efferent arteriolar constriction, which, by increasing the hydrostatic pressure within the glomerular capillaries, would force a greater filtration from the blood during its flow through these structures. 4 That there may be impair­ ment of tubular function is suggested by a measurable decrease in the tubular excretory capacity. Normally, sodium is believed to be reabsorbed from the tubules in 2 phases: (1) an obligatory phase in the proximal tubule and (2) a facultative phase in the distal tubule. The former accounts for reabsorption of approximately 85 per cent of the filtered sodium. 6 With decreased glomerular filtration in con­ gestive heart failure there is a great reduction in tubular sodium load. This apparently results in increased reabsorption of sodium in the obligatory phase, either because of the decreased sodium load or because of malfunction of the tubular apparatus. Some observers believe that increased tubular reabsorption occurs in the distal tubule, also, and contributes further to the total retention of sodium. Other factors in the mechanism of sodium and water retention remain to be evaluated. There is increasing evidence that the pituitary and adrenal glands