THE PHYSICAL EXAMINATION OF THE HEART AND ARTERIES
=Heart Boundaries=
In order to be able to estimate the departures from normal in the
boundaries of the heart, it is essential that there be a definite
appreciation of the boundaries of the normal heart in relation to the
chest wall.
It is frequently stated that the right limit of cardiac dullness is
normally, in the adult, just at the right border of the sternum. This is
not strictly accurate. Careful dissections at the autopsy table and
x-ray plates of the chest made at a distance of two meters from the tube
show that the border of the right auricle is from one to one and a half
and even two centimeters from the edge of the sternum at the level of
the fourth rib, and on the living subject this can be also demonstrated.
The right border of the heart usually is from 3 to 4 cm. from the
midsternal line at the level of the fourth rib.
Again there is a term used in defining the apex, known as the point of
maximum impulse. As this does not always coincide with the apex beat and
with the outer lower left border of the heart, it would be better to use
the term apex beat.
Normally, then, the cardiac dullness, the so-called relative cardiac
dullness, begins above at the upper border of the third costal
cartilage, as a rule, and taking a somewhat curved line with the
concavity inward, descends to the fifth interspace or beneath the fifth
rib from 9 to 10 cm. from a line drawn through the center of the sternum
parallel to its length, the midsternal line. This seems to me to be a
better method of recording the size of the heart than by the lines
commonly used; viz., the nipple, or midclavicular, or parasternal line.
Below, the cardiac dullness is merged into the tympany from the stomach
and the dullness from the liver. At the sixth right costosternal
articulation there is a sharp turn upwards forming at that point with
the liver the cardiohepatic angle. At the fourth right cartilage or the
third interspace, the dullness is from one to two centimeters from the
edge of the sternum. We have then a somewhat pear-shaped area or
triangular area with the apex at the apex of the heart. The so-called
absolute cardiac dullness does not appear to me to be of any great
significance. In reality it is the limit of lung resonance and may be
greater or less, not so much on account of variations in the size of the
heart, as of variations in size of the lungs and shape of the chest
wall.
The really crucial question which should always be asked is, Is the
heart enlarged or decreased in size? The position of the apex beat alone
can not determine this, neither can the limit to the right of the
sternum. The distance between these two points and the depth of the
dullness at a distance of 5 cm. from the midsternal line on the left
side, will give the size of the heart as nearly as can be obtained in
the living subject. A series of measurements in normal adults average 13
to 14 cm. and 9 to 10 cm. respectively. For women they are about 1 cm.
less in each direction.
The elaborate mechanism known as the orthodiagraph is probably the best
means of determining the actual limits of the heart, but few men have
such an expensive instrument, and, moreover, at the bedside such an
instrument could not be used. From comparative measurements I concur in
the belief of those who affirm that careful percussion will furnish
equally as accurate limits.
The first step in making an examination of the heart is to expose the
patient's chest in a good light, and, sitting at his right side,
carefully inspect the chest. The position of the apex beat, heaving,
bulging, retraction of interspaces, etc., can easily be seen if
visible. After careful inspection has given all the data which it is
possible to obtain, one next lays the palm of the hand over the heart
and attempts to palpate the apex beat. The thrust of the apex in a
hypertrophied heart can readily be felt, and one can feel whether the
heart is regular, irregular, intermittent, or has other change in
rhythm. The shock of the closing valves, particularly the aortic, can be
felt, and that and the forcible apical impulse are very suggestive signs
of hypertrophy and hypertension. Thrills may also be felt and can be
timed in relation to the heart cycle.
=Percussion=
It is to percussion that we next proceed, and for the data in regard to
the size of the heart, it is, for our purpose, the most valuable of all
the physical methods of heart examination.
First and foremost we wish by percussion to learn the actual size of the
heart, in other words what is ordinarily called the relative cardiac
dullness. With the absolute dullness we are not concerned. That
irregular area represents, as has been said, actually the =limits of
lung resonance=. The heart may or may not be covered with lung; there
may or may not be the incisura cardiaca. What I wish to insist upon is
that the size of the area of absolute dullness can give us no data in
regard to the size of the heart. What we must endeavor to learn is the
actual size of the heart as nearly as our crude means will permit.
Light, very light, almost inaudible percussion, what Goldscheider called
"Schwellungsperkussion," must be practiced. Use the middle finger of the
right (left) hand as the hammer and the last joint of the middle finger
of the left (right) hand pressed firmly against the chest, as
pleximeter. I believe it is better to place the pleximeter finger
parallel to the boundary to be limited although some place the finger
perpendicularly, that is, pointing toward the boundary. Now and then it
helps to bend the pleximeter finger at the second joint, hold it
perpendicularly to the chest wall, and strike the joint directly in line
of the finger. This in my hands has been of great assistance in
percussing the limits of the heart dullness. Pottenger's "light touch
palpation" is a modification of the light palpation and, to my mind, has
no very special advantages. Auscultatory percussion is of great value at
times. The bell of the stethoscope is placed over the portion of heart
uncovered by lung (should such be the case), and with this point as a
center the chest is lightly and quickly tapped along radii converging
toward the stethoscope. One soon learns to recognize the change of pitch
as the tapping reaches the border of the heart. It is well to use all
methods, especially in difficult cases, and to compare the results.
Personally I have found that by light percussion I can limit with much
accuracy the upper, right, and left borders of the heart.
There is much to be gained by using light percussion. Strong blows set
in vibration not only the underlying structures, but also more or less
of the chest wall. We wish to avoid this source of error, we do not wish
to differentiate by pitch alone. Finally one's pleximeter finger
becomes, after long practice, so sensitive to changes in the resonance
of structures lying below it, that there is actual feeling of impairment
to the slightest degree. This delicate touch is what we should endeavor
to cultivate.
It is at times of advantage to use immediate percussion. This is done by
bending the fingers of the striking hand, bringing the tips in a line
and striking the chest lightly with the four fingers as one finger. Some
find it easier to percuss the dullness due to the heart in this way than
by mediate percussion.
The little hammer and hard rubber, celluloid, bone, or ivory pleximeter
does not seem to me to be nearly as good as the fingers. Moreover, one
always has his hands, but may forget his hammer and pleximeter.
=Auscultation=
In auscultating the heart I prefer the binaural stethoscope of the Ford
pattern. The recent substitution of an aluminum bell for the hard rubber
bell is an improvement. Personally I do not favor the phonendoscope or
any of the new patent non-roaring instruments now for sale by urgent
instrument makers. The phonendoscope has its uses, for example in
auscultating the back when a patient is lying in bed or in listening to
the heart sounds when a patient is under an anesthetic; but for
differentiating the murmurs and for heart diagnosis, I much prefer the
regular bell stethoscope.
In arteriosclerosis the two places over which it is important to listen
are the apex and the second right cartilage, the aortic area. Over the
former, one gains data in regard to the strength of the heart as
indicated by the first sound, over the latter point, one learns of the
tension in the aorta by the character of the sound produced when the
aortic valves close.
The hypertrophy of the heart in arteriosclerosis is invariably due to
the enlargement and thickening of the left ventricle. From the nature of
the position which the heart assumes in the thorax, this enlargement is
downward and to the left. The apex beat will therefore be found in the
fifth or sixth interspace, and definitely at an increased distance from
the midsternal line. As stated above, it is most important that this
distance be accurately measured and put down in the notes of the case
for future reference. No satisfactory prognosis can be given unless this
is done, for the gradual increase or the decrease under treatment in the
size of the heart can thus be definitely known, and, knowing the other
factors, a prognosis may be given which will be of some value to the
patient.
=The Examination of the Arteries=
It is exceedingly difficult at times to affirm definitely that an
artery, the radial for example, is actually sclerosed. Much depends on
the sensitiveness of the fingers of him who palpates, and much upon the
relation of the palpated artery to the surrounding, chiefly underlying,
structures. In the examination of arteries it is well to inspect the
body for the pulsations caused by them. Frequently an exceedingly
tortuous artery, such as the brachial, may be seen throughout its whole
extent and yet the radial appear little, if any, thickened by palpation.
Again the artery of a pulse of high tension which is small in size but
full between the beats, may not be as sclerosed as one which collapses
and feels much softer. It is difficult to obtain accurate data in regard
to the tension in an artery by feeling it with the fingers of one hand.
One should use both hands. With the middle finger of the right (left)
hand the artery is compressed peripherally, that is, nearest the wrist.
The blood is then pressed out of the artery with the middle finger of
the left (right) hand, so as to obliterate completely the pulse wave and
the two or three inches between the middle fingers are felt with the
index fingers. By holding the finger firmly on the artery near the wrist
so as to block any wave that may come through the palmar arch by
anastomosis with the ulnar artery and by releasing pressure on the
proximal middle finger, some idea may be had of the degree of pulse
tension. However, no amount of practice can more than approximate the
tension and when one is surest that he can tell how many millimeters of
pressure there are, he is apt to be farthest wrong when he checks his
guess with the sphygmomanometer.
Much may be learned from carefully palpating the peripheral arteries,
and, as a rule, the sclerosis of these arteries means general
arteriosclerosis, although there are many exceptions to this.
A more recent method, and one which in the author's hands has been found
to be valuable, is that proposed by Wertheim-Salomonson who palpates the
artery not with the ball of the finger but with the fingernail. The
finger is held so that the nail is perpendicular to the surface of the
skin and the artery is felt with the end of the nail. The sensation is
perceived at the root and makes use of all the sensitive nerve endings
there. In this way it is possible to feel the arterial wall distinctly,
and a little practice will enable one to determine whether or not the
vessel wall is thickened. It is also possible to determine with a
considerable degree of accuracy the diameter of the artery and the size
of the wall when the current is cut off by pressure on the proximal side
of the artery. It is best to have a firm background when this
"fingernail" palpation is used. This may be obtained by palpating the
radial artery against the lower end of the radius.
Probably the best method of palpating the arteries, especially the
radial, to determine the degree of sclerosis and thickening, is to use
the tip of the finger and roll it carefully over the artery. The tip of
the finger is exceedingly sensitive and, moreover, it is a firmer
palpating surface than the ball, thus enabling one to appreciate degrees
of sclerosis which could not be differentiated by palpation with the
soft yielding ball. This finger tip palpation is well illustrated in the
figures here shown. (Figs. 57 and 58.)
[Illustration: Fig. 57.--A method of finger-tip palpation of the radial
artery. (Graves.)]
[Illustration: Fig. 58.--Another method of finger-tip palpation of the
radial artery. (Graves.)]
=Estimation of Blood Pressure=
It must be borne in mind at the outset that arteriosclerosis and high
blood pressure are not always associated. As a matter of fact in the
severest grades of senile arteriosclerosis the blood pressure is usually
below the normal for the individual's years. However, as high tension is
a frequent factor in the production of arterial thickening, blood
pressure readings are of importance.
The instrument which one uses is of minor importance provided it is
properly standardized. The most important feature of the instrument is
the cuff. This must be 12 cm. wide and be long enough to wrap around the
arm several times so that the pressure is evenly distributed over the
whole arm and not over a small portion. One mercury instrument we had in
the hospital was reported to be at great variance with a dial
instrument. This mercury instrument was provided with a cuff which was
short and was tied around the arm by means of a piece of tape. This
caused a tight constriction over a small area and rendered the
estimation too high. A new, long tailed cuff easily remedied the
apparent defect in the instrument.
In taking blood pressures the difference from day to day of 10 or even
15 mm. of systolic pressure has no great significance. Fluctuations of
the systolic pressure alone, it is insisted upon, have very little
meaning. One must take the whole pressure picture into consideration and
determine how the picture changes in order to draw any conclusion in
regard to the state of the blood pressure. Failure to pay attention to
this evident point has caused much futile work to be written and
published.
It is well to emphasize again the point that the blood pressure picture
consists of the systolic, the diastolic, the pulse pressure and the
pulse rate.
=Palpation=
Hoover has called attention to the direct palpation of the femoral
artery just below Poupart's ligament as a more accurate index of the
pressure in the aorta than the palpation of the radial artery. Possibly
one can obtain a more accurate estimate of the blood pressure in this
way. This, however, is open to dispute. To estimate the blood pressure
by palpating the radial artery is most deceptive. In about 75 per cent
of cases one can tell fairly well whether the pressure is abnormally
high or abnormally low. Small variations are impossible to determine.
Unquestionably it is most advantageous to get into the habit of
palpating the femoral artery and checking the result with the
sphygmomanometer so that the fingers may be trained to appreciate as
accurately as possible changes of pressure.
It may be that one day when the instrument is needed it is not at hand.
A well-trained touch then becomes a great asset.
=Precautions When Estimating Blood Pressure=
There are certain precautions which must be strictly observed when
deductions are drawn from the manometer readings. The psychic factor
must be reckoned with. Any emotion may cause marked variations in the
pressure. Excitement and anger are especial sources of error. Even the
slight excitement arising from taking the first blood pressure on a
nervous patient especially is apt to give false values. Usually the
readings must be taken many times at the first sitting and the first few
may have to be set aside. Worry is a potent factor in raising the
pressure. A walk to the physician's office, especially if rapid, has its
effect.
The position of the patient when the blood pressure is taken is
important. Usually in the office the pressure is taken when the patient
sits in a chair. He should assume a relaxed, comfortable attitude. The
readings should be made at the same time of day and at the same interval
between meals. The pressure in both arms should be measured and
comparisons should be made only between readings on the same arm. These
precautions may seem useless and even somewhat trivial, and the
conditions difficult to control. But unless they are carefully observed
the readings will be false, no comparisons can be drawn between the
readings on different days, and the instrument will most probably be
blamed. I have known this to happen so often that I can not emphasize
too strongly the importance of controlling all the essential conditions
which go to make accurate work.
=The Value of Blood Pressure=
In the past few years there has been a veritable avalanche of blood
pressure instrument salesmen who have covered the country, sold
instruments, and have made many startling claims for the instrument.
They have emphasized its value out of proportion to what the instrument
can do even in the hands of one familiar will all the defects.
Consequently it is not necessary to emphasize the value of blood
pressure. It seems best to utter a few words of caution in regard to its
interpretation.
The value lies not in the occasional estimation compared with some other
one reading, but in the frequent estimation and in the visualization of
the blood pressure picture. For the great majority of diseases the blood
pressure has no particular value except to show that the circulation is
not materially disturbed. The limits of normal are rather wide, so that
consideration of the patient's age, sex, build, etc., will give us some
idea of a base line, so to speak, for any one person. Wide departures
from relatively normal figures are important, but are not diagnostic or,
rather, pathognomonic. I can not help but feel that the diastolic
pressure is _the_ most important part of the blood pressure picture.
Persistent high diastolic pressure means increased work for the heart,
which, if acting for a long time against the high peripheral resistance,
must eventually hypertrophy. The arteries become thickened, lose their
wonderful elasticity, fibrous tissue is deposited in their walls, and
the vicious circle is established which leads to pathologic
hypertension.
Blood pressure readings must be intimately mixed with brains in order to
be of any great value in diagnosis or prognosis.