The valuable aid to diagnosis, prognosis, and treatment which an accurate test of the heart's functional capacity would afford has made it the object of much clinical research, and although a number of tests have been devised, the validity of each has been seriously questioned and no one has met with general acceptance.
As a preliminary to a new form of exercise treatment for cardiac insufficiency which we have described elsewhere, we investigated several of these tests, more particularly one described by Graüpner. The essential features of his test are the deductions made from the form of the curve of the systolic blood-pressure after measured amounts of work. Although we were unable to confirm his most important results, we believe that the method of making frequent readings of the pulse rate and systolic pressure after measured amounts of work furnishes the key to this problem of determining the heart's efficiency.
BARRINGER TB. THE CIRCULATORY REACTION TO GRADUATED WORK AS A TEST OF THE HEART'S FUNCTIONAL CAPACITY. Arch Intern Med (Chic). 1916;XVII(3):363-381. doi:10.1001/archinte.1916.00080090022003