Test of the Heart's Functional Capacity. 



49 



pounds of work performed in each of these movements. There 

 is a certain amount of work, however, which we cannot estimate 

 in foot-pounds. When a patient stands holding a pair of dumb- 

 bells at his shoulders, work is done as shown by his circulatory 

 reactions, but we cannot estimate it in foot-pounds. This un- 

 known factor may be ignored, however, for our purpose. 



Most adults average 2 feet as the distance through which a 

 bell is pushed from the shoulder to full extension of the arm. In 

 the flexion movement, the distance through which the bell is 

 carried from the side of the body to the shoulder averages from 2 

 feet to 2 feet 6 inches. Now if a 5 pound bell is pushed through 

 2 feet, 10 foot-pounds of work are done. If the total number of 

 pushes are 20, 200 foot-pounds are done. For the sake of com- 

 parison, the time it takes a patient to do any quantity of work 

 should be noted. 



If the patient whose heart is to be tested has but recently 

 recovered from an attack of cardiac insufficiency it is well to start 

 with a pair of five-pound bells, the patient sitting on a stool. 

 Two hundred foot-pounds of work are then given either by flexing 

 or extending the bells alternately. The pulse-rate and blood-pres- 

 sure are taken every 30 or 60 seconds according to the examples 

 given on a preceding page. After the pressure and pulse have 

 returned to the original level, 300 or 400 foot-pounds are done in 

 the same way. The work is increased with each experiment until 

 we reach a delayed rise in blood-pressure. The experiment which 

 has caused a delayed rise should always be repeated after a jew minutes 

 rest with a slightly increased amount of work for the purpose of con- 

 firmation. When once the amount of work which will produce a 

 distinct delayed rise in blood -pressure is ascertained, it is quite 

 remarkable how slightly the results vary upon a repetition of the 

 experiment with the same or increased work. Yet if our test is 

 valid this should be so. 



The Testing of Patients whose Cardiac Capacity Exceeds 

 an Ability to Perform 100 Foot-Pounds of Work 

 in 60-90 Seconds. 



People with normal hearts, or patients with well compensated 

 heart lesions, afford a more difficult problem in mechanics when 



