Tissue change is often impeded because of incomplete oxygenation of blood and sluggish circulation in capillaries and lymphatics. Diet, it is true, will not correct these conditions; nevertheless an accumulation of nitrogenous waste and of the products of abnormal fermentation in the alimentary tract increases the ill effects of such imperfect metabolism. This plainly shows that meats must be used sparingly, if at all, and gastrointestinal indigestion prevented. More can be done to correct faulty metabolism by graduated exercise, hydrotherapy, sunshine, and fresh air than by diet.

When anemia exists, the diet may have to be modified so as to remove it. (See chapter VII.)

The kidneys so often become incompetent because of passive congestion that the diet must at times be modified to meet this condition. A milk diet is then of great utility, as it stimulates diuresis and lessens the formation in the gastrointestinal canal of irritants that may be the cause of grave renal changes, and sometimes of mild toxemia or even genuine uremia. The greatest degree of renal incompetency occurs when the kidneys become waterlogged because of general edema. Then there is often almost a suppression of urine. Abstinence from beverages is unavailing to promote reabsorption of dropsical fluid, because the organs of elimination are no longer active. The drinking of milk and water tends to increase the dropsy. Diet will, therefore, not effect relief. Under such circumstances reliance must be placed upon incisions at the ankles through which the fluid filling the tissues may be drained, or upon drainage effected by inserting numerous small metal tubes into the dropsical extremities. When anasarca is relieved, the kidneys once more become active.

So long as dropsy is moderate and the kidneys are functionally active it may be checked and frequently lessened by abstemiousness in the use of fluids and of foods rich in water. If diaphoresis and catharsis are at the same time provoked, it will be lessened with greater certainty. When anasarca is great, the fluid must be removed by the mechanical means just mentioned. It is also only in exceptional cases that dropsy into the abdominal cavity can be relieved by any other than mechanical means.

Dyspnea on exertion is noticeable in the mildest cases of cardiac weakness, and constant and considerable dyspnea and cyanosis in the severer ones. It is a distressing and sometimes a dangerous symptom. It is commonly due to varying degrees of passive congestion. Asthenia, bronchitis, brown induration, of the lungs, edema, dropsy into the pleurae, pericardium, and abdominal cavity, gastric and intestinal distention, are the factors that aggravate it. Dietetic measures will effect little relief except when the dyspnea is largely due to gastric and intestinal distention. Flatulence must be prevented by avoiding overfeeding and especially by avoiding the amylaceous foods. Distention with fluids and solids may be prevented by limiting the quantity ingested and by stimulating their elimination.

Irregularity and rapidity of the heart's action are often provoked even in cases of moderate heart weakness, by slow digestion, by flatulence, and by constipation. These conditions must be corrected whenever the heart is excessively quick and irregular.

It is the uniform testimony of clinicians writing upon heart diseases that it is best that alcoholics should not be used, or, if at all, very sparingly; the fermented beverages, being likely to produce flatulence and sour stomach, should certainly be avoided entirely. Distilled beverages are sometimes used as stimulants, but less often than formerly, because other drugs are more certain in their action and less liable to abuse. Tobacco must be forbidden when the heart is weak. It is especially likely to make it more irregular and more dilated.

The need of preventing constipation has so frequently been referred to that it is hardly necessary to add emphasis. In these cases, diet does not help matters much, for the sweet fruits, sugars, and coarse breads, which are the most important laxative foods, are frequently counterindicated.

When cardiac weakness is due to fatty infiltration of the heart muscle, as in cases of obesity, the diet described elsewhere as appropriate to that condition must be prescribed.

Palpitation

Consciousness of rapid or irregular beating of the heart is often, but not always, caused by indigestion. Flatulence is especially likely to cause it. Overeating and indigestible foods must be avoided, especially the eating of such as lead to flatulence. Tea, coffee, and tobacco must also be forbidden. The bowels must be thoroughly and regularly moved.