Heart failure, generally, has been recognized to result in slowing the circulation of the blood. The volume of blood passing through the body at any moment is numerically represented by the product of the pulse rate and the output per heart beat. Since the pulse rate is generally increased in cases of heart failure, it appears reasonable to infer that the slowing of the circulation is due to a greater relative decrease in the output per beat.
The output of the heart per minute in man has been measured by numerous workers.1 In normal subjects, it has been found to vary between 3.8 and 6 liters. Thus, Lowey and von Schrotters (1903) give 4.2 liters; Plesch (1909), 3.1-5.3; Markoff, Muller and Zuntz (1912), 4-6; Muller (1913), 4.5-5.5; Bornstein (1913), 5-6; Christianson, Douglas and Haldane (1914), 4; Means and Newburgh (1915), 4-4.5; Lundsgaard (1916), male 5.3, female 3.8, and Meakins, Dautrebande