The Function of the Kidneys in Patients Suffering From Chronic Cardiac Disease Without Signs of Heart Failure

This study is concerned with the function of the kidneys in patients suffering from chronic heart disease during periods when they show no signs of heart failure.Studies of renal function during attacks of heart failure have of course been numerous.With the introduction of each new test of renal function its usefulness in cardiac patients has been explored, often however without attempting to correlate it with other tests already in use.Following the introduction of phenolsulphonephthalein by Rown- tree and Geraghty (1912), investigations by Rowntree, Fitz and Ger- aghty (1913), Rowntree and Fitz (1913), Rowntree, Marshall and Baetjer (1915), Frothingham and Smile (1914) and Agnew (1915) were published.The outcome of all these studies is the same, namely, that excretion of this substance is much reduced, if there is a marked degree of chronic passive congestion; with restoration of compensation excretion again becomes normal.McLean (1915) studied these cases from a slightly different point of view.Instead of measuring the ex- cretion of a substance introduced from without, he estimated a natural function, in this case urea excretion and found that the index of ureas excretion was low during decompensation, but increased as the signs of heart failure disappeared.As an indication of the state of the circula- tion, it ran parallel to the test of Rowntree and Geraghty (1912).In all these investigations the emphasis has been placed more or less upon the state of the kidneys as a phase of heart failure.Important though it is to be aware of this matter, it is equally, perhaps more important to know whether the kidneys are essentially damaged or whether their behavior merely reflects the state of the whole organism, caught as it is, in the process of heart failure.For this reason we have examined the