In 1916 Peabody, Meyer and DuBois1 found that patients with compensated cardiac disease showed no increase in basal metabolism. Nine out of twelve cases with dyspnea showed elevations in heat production above normal. They used both direct and indirect calorimetry. The respiratory quotients were between 0.73 and 0.94. They considered the earlier work of others of questionable accuracy because the respiratory quotients were too low.
Peabody, Wentworth and Barker2 in 1917 studied twenty-four cases of cardiac disease and used as an additional index the vital capacity. Their results indicated that the rise in heat production was related to the degree of cardiac insufficiency. In direct accord with these observations Aub and DuBois3 reported the respiratory exchange to be increased in cases of hypertension with dyspnea.
The subsequent studies of Peabody, Wearn and Tompkins4 on "irritable heart" in soldiers, and of Boothby and Sandiford5 on a large series of various types