Disturbances of the Heart | Page 6

being most common.
Of course it is generally understood that children have a higher pulse
rate than adults; that women normally have a higher pulse rate than
men at the same age; that strenuous muscular exercise, frequently
repeated, without cardiac tire while causing the pulse to be rapid at the
time, slows the pulse during the interim of such exercise and may
gradually cause a more or less permanent slow pulse. It should be
remembered that athletes have slow pulse, and the severity of their
condition must not be interpreted by the rate of the pulse. Even with
high fever the pulse of an athlete may be slow.
Not enough investigations have been made of the rate of the pulse
during sleep under various conditions. Klewitz [Footnote: Klewitz:
Deutsch. Arch. f. klin. Med. 1913, cxii, 38.] found that the average
pulse rate of normal individuals while awake and active was 74 per
minute, but while asleep the average fell to 59 per minute. He found
also that if a state of perfect rest could be obtained during the waking
period, the pulse rate was slowed. This is also true in cases of
compensated cardiac lesions, but it was not true in decompensated
hearts. He found that irregularities such as extrasystoles and organic

tachycardia did not disappear during sleep, whereas functional
tachycardia did.
It is well known that high blood pressure slows the pulse rate; that low
blood pressure generally increases the pulse rate, and that
arteriosclerosis, or the gradual aging of the arteries, slows the pulse,
except when the cardiac degeneration of old age makes the heart again
more irritable and more rapid. The rapid heart in hyperthyroidism is
also well understood. It is not so frequently noted that hypersecretion of
the thyroid may cause a rapid heart without any other tangible or
discoverable thyroid symptom or symptoms of hyperthyroidism. Bile in
the blood almost always slows the pulse.
INTERPRETATION OF TRACINGS
The interpretation of the arterial tracing shows that the nearly vertical
tip-stroke is due to the sudden rise of blood pressure caused by the
contraction of the ventricles. The long and irregular down-stroke means
a gradual fall of the blood pressure. The first upward rise in this gradual
decline is due to the secondary contraction and expansion of the artery;
in other words, a tidal wave. The second upward rise in the decline is
called the recoil, or the dicrotic wave, and is due to the sudden closure
of the aortic valves and the recoil of the blood wave. The interpretation
of the jugular tracing, or phlebogram as the vein tracing may be termed,
shows the apex of the rise to be due to the contraction of the auricle.
The short downward curve from the apex means relaxation of the
auricle. The second lesser rise, called the carotid wave, is believed to be
due to the impact of the sudden expansion of the carotid artery. The
drop of the wave tracing after this cartoid rise is due to the auricular
diastole. The immediate following second rise not so high as that of the
auricular contraction is known as the ventricular wave, and corresponds
to the dicrotic wave in the radial. The next lesser decline shows
ventricular diastole, or the heart rest. A tracing of the jugular vein
shows the activity of the right side of the heart. The tracing of the
carotid and radial shows the activity of the left side of the heart. After
normal tracings have been carefully taken and studied by the clinician
or a laboratory assistant, abnormalities in these readings are readily

shown graphically. Especially characteristic are tracings of auricular
fibrillation and those of heart block.
TESTS OF HEART STRENGTH
If both systolic and diastolic blood pressure are taken, and the heart
strength is more or less accurately determined, mistakes in the
administration of cardiac drugs will be less frequent. Besides mapping
out the size of the heart by roentgenoscopy and studying the
contractions of the heart with the fluoroscope, and a detailed study of
sphygmographic and cardiographic tracings, which methods are not
available to the large majority of physicians, there are various methods
of approximately, at least, determining the strength of the heart muscle.
Barringer [Footnote: Barringer, T. B., Jr.: The Circulatory Reaction to
Graduated Work as a Test of the Heart's Functional Capacity, Arch. Int.
Med., March, 1916, p. 363.] has experimented both with normal
persons and with patients who were suffering some cardiac
insufficiency. He used both the bicycle ergometer and dumb-bells, and
finds that there is a rise of systolic pressure after ordinary work, but a
delayed rise after very heavy work, in normal persons. In patients with
cardiac insufficiency he finds there is a delayed rise in the systolic
pressure after even slight exercise, and those with marked cardiac
insufficiency have