Evening star. [volume] (Washington, D.C.) 1854-1972, 1931-01-14
HEARTS CAPRICE
STUDIED IN TESTS
Wide Variations Found in
Pulse Beats of Same Indi-
viduaI at Various Times.
BY THOMAS r. HENRY.

The heart is a capricious organ, both
sentimentally and physiologically.
Astonishing variations in the rate of
the individual heart beat from day to
day. as registered by the pulse, have
been found in tests of Government
clerks here by the Public Health Service.
The same individual, it was found, will
vary from so to 116 beats per minute
when the pulse rate is taken on differ
ent days.
While it has long been known that the
pulse rate differs greatly for different
persons, ranging from about so to more
than 100 beats per minute and striking
an average somewhere between 20 and
80, the fact that variations almost as
great can be found consistently in one
person over a long period came as a
revelation to the public health surgeons.
Range Found Wide.
One woman ranged from So to 90
beats a minute mans record ran
from so to 116. The experiment was
made with IL men and IL women over
a period of 16 months, with between
los and 100 observations on each per-
son. All were engaged in sedentary
clerical work and were called to the eX-
aminations day after day from their
ordinary tasks. Few took much eXer-
else outside their offices. There was no
unusual physical exertion which would
affect the rate of the heart
The examiners expected pulse rates
higher than normal for the individual
at the first examination. when there
would be some excitement and sub
conscious fear which would release in
the blood stream small amounts of the
powerful hOrmone adrenalin which
greatly speeds the heart. This effect
they expected to disappear as the ex-
aminations lost their novelty and be-
came only part of the days routine.
Readings Made Daily.
The pulse readings were taken daily,
except Saturday and Sunday during
March, April and May. Then they were
discontinued until December, after
which they were taken three times a
week through May. They found that
the pulse rate was approximately three
beats minute faster during the second
period than the first, indicating the pos
s1bility of a seasonal variation of the
heart. This is not conclusive. however,
because of the limited data and the fact
that observations were not taken for IL
consecutive months.
Some persons. it was explained at
the Public Health Service, have nor
mally slow hearts, probably due to the
constitution of the nervous system
such that the inhibitory nervous control
OF the organ is unusually strong. The
normal rate may not be much above
so beats minute. When such indi-
vtduals are sick they often puzzle ply
Sicians, who do not know of their pc
culisrity. The fast heart also is COM
mon, and the rate is greatly aggravated
in an unfamiliar situation In examin-
ing applicants for positions the Public
Health Service itself always discounts
an apparently abnormally fast pulse
rate until the applicant can be re-exam-
ined while not under nervous tension
But once pulse rate has been estab-
lshed. it generally has been accepted
as characteristic Of the individual
within reasonable limits. A marked
change would lead to the suspicion that
something was wrong.
Average for Men Is 76.
The average pulse rate of the men
was rs and of the women 1873, giving
a tentative average Of TAG for the
Washington clerical workers. An aver
age Of 81.l was found by an early study
by the Public Health Service Of 10000
industrial workers, subjected TO more
physical exercise. The average for the
clerks is ihconclusive, because of the
small number tested
Some clerks, the examinations showed
have very constant hearts. One woman
ranged only from 60 to 81. and one
man only from 81 to SO. One woman
however, had rate of SO on days, ST
on days, 60 on days, "a on 16 days
SO on % days, 70 on % days, 80 or
10 days and 100 on / day. The pulse
rates were taken without consideration
of other physical conditions. except that
the clerks were well enough to be al