bad.

Barach [Footnote: Barach: Am. Jour. Med. Sc., July, 1916, p. 84]
presents what he terms "the energy index of the circulatory system."
He has examined 742 normal persons, and found that the pressure
pulse was anywhere from 20 to 80 percent of the diastolic pressure
in 80 per cent of his cases, while the average of his figures gave a
ratio of 50 percent; but he does not believe that it holds true that
in a normal person the pressure pulse equals 50 percent of the
diastolic pressure. Barach does not believe we have, as yet, any
very accurate method of determining the cardiac strength or
circulatory capacity for work. He does not believe that the estimate
of the pressure pulse is indicative of cardiac strength. He believes
that the important factors in the estimation of the circulatory
strength are the systolic pressure, which shows the power of the
left ventricle, the diastolic pressure, which shows the
intravascular tension during diastole as well as the peripheral
resistance, and the pulse rate, which designates the number of times
the heart must contract during a minute to maintain the proper flow
of blood. He thinks that these three factors are constantly adapting
themselves to each other for the needs of the individual, and he
finds, for instance, that when the left ventricle is hypertrophied
and the output of blood is therefore greater, then the pulse will be
slowed. His method of estimation is as follows: For instance, with a
systolic pressure of 120 mm. and a diastolic pressure of 80 mm.,
each pulse beat will represent an energy equal to lifting 120 mm.
plus 80 mm., which equals 200 mm. of mercury, and with seventy-two
pulse beats the force would be 72 X 200, which equals 14,400 mm. of
mercury. He finds an average circulatory strength based on examining
250 normal individuals by the index, which he terms S, D, R