The observations to be presented in this report constitute a part of a general study of the functional alterations concerned in the production of the clinical picture of congestive heart failure. One method of obtaining information concerning such alterations is to inquire into the mechanism whereby therapeutic measures produce clinical improvement. It is now generally recognized not only that digitalis is the sovereign remedy for heart failure in patients with auricular fibrillation but that this drug is often beneficial to persons with regular rhythm. In the former group of patients clinical improvement may be ascribed to the dramatic slowing of the heart, but in the latter group changes in the cardiac rate are usually slight, and an adequate explanation for the benefits from digitalis has yet to be offered. According to some investigators, the effects are dependent on an increase in the output of the heart per minute; other authors
Ben J. Friedman (1935) studied this question.