The diet and theophylline are considered together in the treatment of cardiac failure because of their related influence on the function of the heart. The diet provides the source of energy on which the heart is ultimately dependent, and the theophylline, in addition to its diuretic effect, increases the coronary circulation. This drug is most effective in the arteriosclerotic type of cardiac failure in which a defective coronary circulation is an important factor. The patient with advanced cardiac failure frequently complains of abdominal discomfort, which is often induced by a disturbed gastro-intestinal function. In those in whom the cardiac failure has extended over a long period, there may be a loss of from 20 to 30 pounds (9 to 13.6 Kg.). This means that the patient either has not received sufficient food to maintain a normal weight or has been unable to utilize it in the form provided. Under these