From the Author. 
ABSENCE OF RESONANCE IN THE FIFTH 
RIGHT INTERCOSTAL SPACE, 
DIAGNOSTIC OF 
PERICARDIAL EFFUSION. 
By T. M. ROTCH, M.R. 
OF BOSTON. 
Reprinted from the Transactions of the Massachusetts Medical Society. 
BOSTON: 
DAVID CLAPP & SON, PRINTERS, 
5G4 Washington Street, 
1 8 7 8 . ABSENCE OF EESONANCE IN THE FIFTH 
RIGHT INTERCOSTAL SPACE, 
DIAGNOSTIC OF 
PERICARDIAL EFFUSION. 
By T. M. ROTCH, M.D. 
OF BOSTON. 
Reprinted from the Transactions of the Massachusetts Medical Society 
BOSTON: 
DAVID CLAPP & SON, PRINTERS, 
504 Washington Street, 
1 8 78. ABSENCE OE RESONANCE IN TIIE EIETII RIGHT 
INTERCOSTAL SPACE, 
DIAGNOSTIC OF 
PERICARDIAL EFFUSION.* 
My attention was first directed to the investigation of the 
commonly received views concerning the area of dulness in 
pericardial effusion, by the numerous cases of effusion into 
the pericardium found at post-mortem examinations, where 
such effusion had not been diagnosticated during life, although 
the patients had been in the hands of most competent clinical 
diagnosticians. 
On inquiry, I learned from very careful investigators, 
that the rules laid down by authorities on this subject were 
often totally inadequate for purposes of diagnosis, and the 
opinion of these physicians is well represented, when ex- 
pressed in the words of Professor Calvin Ellis, who, when 
questioned regarding the subject, said that "he thought the 
rules laid down by authors for determining pericardial effu- 
sion by the pyramidal form of the area of flatness, misleading 
and insufficient.” Dr. Henry I. Bowditch also concurs in 
this opinion. 
Influenced by the experience of these eminent physicians, 
I began, about nine months ago, a series of experiments to 
determine, if possible, the actual shape which the effusion, 
when present, does take, and the results of these experiments 
will be given in this paper. 
What, then, are the views held upon this subject by the 
numerous authorities, who have written about it since Galen, 
Forestus and llondelet first spoke of pericardial effusion? 
* Read at the Annual Meeting of the Massachusetts Medical Society, June 
11, 1878. 4 
ABSENCE OF RESONANCE, ETC. 
Albertini, and in like manner Morgagni mention the diffi- 
culties presented in the diagnosis, while Auenbrtigger first 
gave the symptom of proecordial percussion dulness, Laennec 
at the same time doubting the possibility of diagnosticating 
pericardial effusion with any certainty, and this author did 
not recognize the disease by percussion, Louis being the 
first French author who speaks of it, while prcecordial dul- 
ness, as a symptom, is first elaborately described by Skoda 
and Kolletschka. 
We will not here consider the various complications of 
the disease which may arise and render its diagnosis of 
greater difficulty; these I expect to speak of in a future 
paper, considering at present merely the diagnosis by per- 
cussion of a simple serous or sero-fibrinous effusion into the 
pericardium, with the heart healthy or diseased as a com- 
plication, but the lungs and pleura normal, no adhesions, 
and in fact nothing else abnormal in the thorax or abdomen. 
Reviewing the ideas of representative authors on this 
subject, first, Skoda writes, "It is necessary to have a large 
amount of fluid to cause an increase of dulness. The 
dulness depends on the amount of retraction of the lung. 
"As the heart is heavier, that is, has a greater specific 
gravity than any exuded fluid, it lies as deeply as possible, 
the fluid standing as high as possible ; this is when the fluid 
is in small amount, and is always the case excepting when 
the pericardium is relaxed, or when adhesions are present in 
the upper part of the pericardium ; thus at first when the 
amount of fluid is comparatively small, the increase of the 
dulness is vertical, that is, in the long diameter of the heart, 
while increase in breadth only takes place after the amount 
of fluid has increased still further, and when it reaches 1,000 
cubic centimetres, as a rule the percussion dulness extends 
from the second left costal cartilage to the lower edge of the 
thorax, and in breadth from the right edge of the middle 
piece of the sternum to the left axillary line.” DIAGNOSTIC OF PERICARDIAL EFFUSION. 
5 
Stoffela, reporting Oppolzer’s lectures, says : "The symp- 
toms of pericardial effusion are in some cases very evident, 
while in others they are so unpronounced as to cause the 
greatest difficulty in the diagnosis. Percussion shows that 
the exudation begins at the base of the heart, where the great 
vessels join the heart, and hence as the pericardium at this 
point is most relaxed, so the fluid collects here first and is first 
found here by percussion, thus increasing the long diameter 
of the heart, reaching as high as the third or second rib, 
in the left parasternal line ; then, on the fluid increasing, 
we find the dulness increased in breadth, that is, extending 
from the right edge of the sternum across to the left mam- 
mary line ; this area of dulness has the form of an inverted 
triangle, its base being upwards and its squared apex down- 
wards ; then, on further increase of the effusion, the dulness 
can extend up to the first rib, and the figure becomes less 
and less like a triangle, but, as it increases, the fluid fills up 
the lower part of the pericardium, and we now have a 
triangle, with the base downwards and its truncated apex 
above.” 
Prof. Bauer says, "that the effusion first collects at the 
base of the heart, pushing that organ downwards before it; 
that the dulness has in a majority of cases a certain form, 
namely, that of a truncated cone with the base downwards,” 
and he disagrees with Duchek, who holds "that the form of 
the area of dulness is determined by the lungs retracting,” 
while Bauer contends " that it is the shape of the pericardium 
itself which governs this form.” Bauer also says, "that in 
large exudations the triangle reaches to the second or third 
rib on the left of the sternum, that at times the whole 
sternum may be dull, that the left side of the triangle may 
extend beyond the left nipple to the axillary line, and that 
this may also occur on the right side ; usually, however, the 
dulness extends very little to the right of the sternum, and 
the effusion must have reached 100 cubic centimetres in 
quantity before a diagnosis can be made.” 6 
ABSENCE OF RESONANCE, ETC. 
Paul Niemeyer states, that the exudation is first per- 
ceptible by percussion, when it has reached 250 cubic 
centimetres, and both he and Kunze agree with Oppolzer as 
to the form of the area of percussion dulness, while Gutt- 
mann, Felix Niemeyer, Gerhardt, Jaccoud and Gee appear 
to agree with the views of Skoda on this point. 
Sibson, writing in Reynolds’s "System of Medicine,” says, 
"the fluid collects in the lower part of the percardium, push- 
ing the heart up, so that the apex is above and beyond the 
nipple, and when the effusion is large it assumes a pyramidal 
or pear shape.” He also considers, as does Gee, that it is 
the vertical increase of dulness which is characteristic of 
pericardial effusion, as affording the means of diagnosis from 
an enlarged heart. 
Da Costa states that the shape is "pyramidal,” with the 
base downwards ; while Flint speaks of the area of dulness 
as "pyriform,” with the apex at the sternal notch, and the 
base at the 6th or 7th cartilages, the left boundary extending 
as far as the left nipple, and the right over the right edge of 
the sternum. 
The rules for making the diagnosis of pericardial effusion, 
then, being exactly laid down by these authors, have they, 
or have they not, proved adequate, practically, for such 
diagnosis? The following instances will, it seems to me, 
tend to show that they have not. 
First, I would cite the case reported to me by Professor 
Ellis, where the diagnosis of pericardial effusion was made 
by one of the best trained of his advanced students, strictly 
according to rule, and so logically drawn up that Professor 
Ellis could not gainsay the diagnosis, so long as he admitted 
the triangular form of flatness to be characteristic of pericar- 
dial effusion ; and yet there was no doubt, judging by other 
prominent symptoms, that the area of increased praecftrdial 
flatness was caused by an enlarged heart. DIAGNOSTIC OF rERICARDIAL EFFUSION. 
7 
Next, by permission of Dr. T. B. Curtis, I will read an 
extract from his letter to me on this subject, giving bis 
reasons for doubting the correctness of the established rules 
for diagnosticating effusion. Dr. Curtis says : "When I 
was serving as interne in 1870 at the 'Hopital des Enfants 
Malades,’ under Dr. Henri Roger, there was in one of his 
beds a little girl about five years old, who presented all the 
signs of an abundant chronic effusion into the pericardial 
cavity. We had her several weeks under observation, and 
she was an object of particular interest to Dr. Roger, for 
the reason that he had already previously practised puncture 
of the pericardium in a well known case (published in the 
'Union Medicale,’ December, 18G8), and was extremely 
desirous of an opportunity to repeat the procedure. 
"In this case indications of the operation seemed to present 
themselves again, at times in the most urgent manner. 
Repeatedly I saw Dr. Roger mark out the area of dulness 
in his usual minutely careful way, and select the exact spot 
where he would insert the trocar. Before deciding to ope- 
rate, he consulted Dr. Labric, who was also attached to the 
Children’s Hospital, and for whose judgment he had the 
highest regard. The latter, however, persistently advised 
against the proposed puncture, and in deference to his 
opinion the operation was postponed, until finally the child 
succumbed, without the operation having been performed. 
At the autopsy we found no effusion, but an enormously 
dilated heart. 
"So closely, then, in this case were the signs of a copious 
pericardial effusion simulated by dilatation of the heart, as 
to deceive one so skilful as Dr. Roger, fortified by an 
experience of nineteen years as physician to the Children’s 
Hospital, a virtuoso in the art of physical examination, the 
author together with Dr. Barth of a well known treatise on 
auscultation and percussion, and also author of a treatise on 
the semeiology of childhood.” 8 
ABSENCE OF RESONANCE, ETC. 
Allowing that the heart has been tapped by mistake, by 
Baizeau and Roger, and blood withdrawn from the right 
ventricle without apparent harm to the patient, yet this 
accident is not by any means devoid of danger ; and to show 
the great risk incurred in tapping the heart to the left of the 
sternum, with only our present knowledge of the signs of 
effusion, I will present one more instance of unsuccessful 
diagnosis. In the "Gazette dcs Hopitaux,” No. 39, there 
is reported the case of a soldier in the Military Hospital of 
"Groscaillon,” who exhibited symptoms of pericardial effu- 
sion and disease of the aortic valves following from attacks 
of acute articular rheumatism. The dyspnoea led the sur- 
geons to introduce a No. 1 Potain needle in the third left 
intercostal space, to the depth of four centimetres. No fluid 
appeared, and on leaving the needle free it oscillated syn- 
chronously with the beat of the heart, which h}id been 
punctured ; the patient uttered a sharp cry, took one deep 
inspiration, and was dead. The pericardium was found to be 
much thickened and adherent to the heart at various points. 
The needle had passed over one of these points and wounded 
the centra] organ. 
The experiments which I am about to present to you were 
performed in the Physiological Laboratory of Professor II. 
P. Bowditch, and were all submitted to his inspection. I 
am greatly indebted for very valuable suggestions from 
Professor Bowditch, from his assistant Dr. Garland, and 
from Dr. James J. Putnam. 
My first experiments were made upon dogs, but were 
failures, as to any notable results, for the following reasons : 
1st, that the dog’s pericardium has not the same shape as the 
human pericardium ; 2d, that it hangs more vertically in the 
thorax ; and 3d, that owing to the pleura meeting directly 
in the median line of the sternum, and to the existence of 
an extra pleural cavity under the heart (first spoken of by 
Dr. Garland), it is impossible to enter the pericardium DIAGNOSTIC OF PERICARDIAL EFFUSION. 
9 
without opening the pleural cavity and causing collapse of 
the lung, an accident which materially alters the shape which 
the fluid may assume. 
It was therefore thought best to use the cadaver only ; for 
here we can introduce fluid into the pericardium without 
destroying the relations between the lungs and the heart 
which exist during life ; it was also found by dissection that 
the anatomy of the infant’s thoracic organs corresponds so 
very nearly to that of the adult's, that the introduction of 
fluid into the infant’s pericardium was followed by the same 
relative results as that into the adult’s. 
My results are based upon the injections of sixteen infants 
and four adults. The fluid used was melted cocoa butter, 
which has a specific gravity of 0.90. It will be well to 
state here that I use the term flatness to express entire 
absence of resonance, or what is understood by some Ger- 
man authors as "absolute dulness.” By relative dulness 
I mean diminished resonance. Thus when I speak of the 
flatness of the heart or effusion, I mean that no lung tissue 
whatever is between the pleximeter and such heart or effu- 
sion ; while, where there is more or less lung tissue, I use 
the term relative dulness. Now as opinions are much 
more apt to differ as to relative duluess than as to flatness, 
it is the area of flatness which I shall mark out as charac- 
teristic of effusion, and I would also add, that in order to 
mark out the boundary of the area of flatness correctly, we 
must percuss very lightly from a point of established flatness, 
such as the fifth left costal cartilage, to the right and left and 
upwards, until we come to the encircling resonant border of 
the lung. 
It is needless to mention the various methods of entering 
the pericardium which were employed before satisfactory 
results could be obtained; it is sufficient to state, that 
although by sawing the sternum in the median line the 
pericardium can be entered without perforating the pleural 10 
ABSENCE OF RESONANCE, ETC. 
cavity, yet that by this method the results of percussion are 
rendered void by air not only entering the anterior medi- 
astinum, but also getting into the pericardium itself. 
The method which was finally adopted was as follows : 
The subject was placed in the position of orthopnoea, that 
is, the trunk was bent upon the lower limbs, at an angle of 
about 120 degrees. Tracheotomy was performed and a 
clamped rubber tube attached to the glass tracheal tube. 
The lungs were then inflated, until the area of heart flatness 
corresponded to that marked out in Diagram I., which is 
copied directly from Luschka’s plate, and is, as is stated by 
Luschka, intended to represent the parts in expiration. 
After inflation, the tracheal tube was clamped, so as to 
keep the parts in position, and an incision was made in the 
median line of the abdomen, up to within two centimetres 
of the ensiforin cartilage; the liver and stomach were next 
gently drawn aside, and on palpation of the central tendon 
of the diaphragm, four centimetres below the upper edge of 
the diaphragm and about two centimetres to the left of the 
median line, the heart was felt. This part of the diaphragm 
Avas then carefully drawn down away from the heart, in 
order that that organ should not be punctured, and a dagger- 
pointed trocar, previously filled with melted cocoa butter so 
as to displace the air, was plunged through the diaphragm 
into the pericardial sac; at the same time an assistant 
undamped the tracheal tube, in order that the lungs might 
be free to retract before the fluid. 
When sufficient fluid had entered the pericardium the 
cocoa butter tube was clamped, as was also the tracheal tube. 
The thorax was then carefully percussed and the line of 
flatness marked in ink. After twenty-four hours the sternum 
was removed from above downwards, remaining attached 
below, and we had before us the lungs in position surround- 
ing the hardened fluid, and by replacing the sternum and 
comparing the line previously marked in ink, by means of DIAGNOSTIC OF PERICARDIAL EFFUSION. 
11 
needles, with the line of the lung around the effusion, we 
arrived at very accurate results regarding the shape of the 
area of flatness. 
The fact that on opening the abdomen the diaphragm 
remains arched, and that the lung by means of the tracheal 
clamp retains its position and docs not collapse, warrants 
us in assuming that we can fairly judge of the position of 
the fluid during life by this method of investigation, espe- 
cially as the contractility and distensibility of the lung 
appear to be perfectly retained after death, excepting in 
very cold weather, when it was found necessary to warm the 
cadaver. 
The apparatus for the cocoa butter is a simple wash bottle, 
graded for cubic centimetres. 
w e must now shortly consider the anatomy of the normal 
pericardium and its relation to the heart and lungs. This, so 
far as the adult is concerned, I have taken mostly from 
Ferber, Luschka, Sibson and Shrcetter; while in regard to 
the infant, I have made my own dissections, comparing the 
thoracic organs with those of the adult, and finding, as I 
have above stated, the relation of the parts so nearly ap- 
proximating each other in the two, that the rules which 
govern an effusion in one answer for the other. 
According to Shrcetter and Luschka, in the normal condi- 
tion of the thoracic organs, on expiration, we have the flatness 
of the heart beginning at the junction of the upper border of 
the fourth left costal cartilage, extending outwards and down- 
wards to the left in rather a curved line, with the convexity 
outwards, and keeping from two to three centimetres within 
the nipple, until it joins the flatness of the left lobe of the 
liver; from the same starting point at the fourth cartilage, 
it extends down the left parasternal line, or perhaps a little 
within that line towards the middle of the sternum, until it 
reaches the liver, as seen in Diagram I. This figure is at 
times triangular, especially on deep expiration. We there- 12 
ABSENCE OF RESONANCE, ETC. 
fore may have a triangular area of flatness over the normal 
heart, though it is usually quadrangular. Next, supposing 
that the lungs are removed, we then have exposed to view 
the pericardium as seen in Diagram II., represented by the 
area A, and copied directly from Ferber’s "Situs Phantom.” 
The base of the pericardium is attached to the central tendon 
of the diaphragm, extends upwards enveloping the heart, 
and is attached to the great vessels of the heart between the 
first and second ribs, spreading out on either side of the 
sternum in pyriform shape, most markedly on the left side 
of the sternum, but keeping within the mammary line. 
The lower border of the upper lobe of the right lung 
approaches the right edge of the sternum at about the level 
of the fourth rib ; on the left side, the upper lobe passes 
around the heart down nearly to the sixth rib ; the middle 
lobe of the right lung, in the region between the right 
mammary line and the sternum*, extends from the fourth to 
the sixth rib, where the line of the liver flatness begins. This 
amount of anatomy is sufficient for our purpose at present. 
First, we will consider what takes place when we intro- 
duce a small amount of fluid into the pericardium, picking 
out from my notes a case which may be regarded as typical. 
Jan. 7, 1878, injected by the usual method, through the 
diaphragm, a small amount of fluid into the pericardium of 
an infant of from one to two weeks old. Percussion gave 
an increase of prsecordial flatness, as follows : beginning at 
the sixth rib, about two centimetres to the right of the 
sternum, it passed upwards in a curved line with the con- 
vexity outwards to the fourth right costal cartilage at its 
lower edge, then across the sternum to the upper border of 
the fourth left costal cartilage and outwards and downwards 
to and to the outside of the nipple, passing down to the 
sixth or seventh rib, as is seen in Diagram III. There was 
no vertical increase of flatness. This line of flatness then 
was a semicircle, with its convexity upwards, and with the DIAGNOSTIC OF PERICARDIAL EFFUSION. 
13 
radius of that part of the curve which was to the right of 
the sternum shorter than that which was to the left. What 
was this flatness caused by ? On clamping the trachea and 
removing the sternum, the area of flatness, marked out in 
ink, was found to correspond to that part of the pericardium 
which was uncovered by the lungs : it was found that the 
lower lobes had retracted before the fluid, and that the fluid 
had taken the shape which is represented in Diagram III., 
the normal physiological flatness of the heart forming the 
upper part of the area of flatness, and the effusion the lower 
part. The lungs were then drawn aside and the pericardium, 
with its contained effusion, was seen to present the form 
which is shown in Diagram IV., the effusion apparently 
being drawn up at the sides, where it was thickest, leaving 
a thin layer below, so that the broadest part of the effusion 
about corresponded to the top of the curved line. The 
same result, as to the area of flatness, was obtained when- 
ever a small amount of fluid was introduced, whether in the 
infant or adult, the increase always being in a line with the 
lower part of the sternum, and never vertically. 
Perhaps it will be well to here describe shortly the case 
where I was enabled to determine the first signs of effusion 
in an adult, by the introduction of from 70 to 80 cubic 
centimetres of fluid, which is from 20 to 30 cubic centimetres 
less than the smallest amount laid down by authors as being 
possible to make a diagnosis by. 
April 22, 1878,—subject, a female of medium size, who 
had died of cancer of the rectum : percussion of lungs and 
heart normal; resonance in fifth right intercostal space well 
marked. Dr. Maurice Richardson managed the cocoa butter 
apparatus for me, keeping his eyes on the graduated scale and 
his hand on the clamp ; the trocar was introduced, and I 
proceeded to percuss lightly the fifth right interspace about 
1| to 2 centimetres from the edge of the sternum, until 
decided flatness was found and verified by Dr. Richardson, 14 
ABSENCE OF RESONANCE, ETC. 
who then immediately applied the clamp, when we found 
by our scale that when the flatness first appeared 70 to 80 
cubic centimetres of fluid had been introduced. We then 
found that no vertical increase of flatness had taken place, 
and that the curved line bounding the area of flatness corre- 
sponded to that in Diagram III., the percussion flatness 
extending in the fifth interspace to about 4 centimetres 
from the edge of the sternum. 
Next we will consider the large effusion, where the peri- 
cardium is pretty well filled from top to bottom. 
May 10, 1878, with the assistance of Professor Bow- 
ditch, injected the pericardium of an infant about two weeks 
old, until percussion showed that the pnccordial flatness had 
extended to the nipple on the right, and beyond the nipple 
to the left, in an area corresponding to the front of the 
thorax as high as the fourth ribs, when it approached the 
sternum to within about centimetres, and then passed 
upwards to the sternal notch. 
The distended pericardium, with the lungs removed, is 
represented in Diagram II. by the area A and D. 
Diagram Y. represents the picture, disclosed to our view, 
on clamping the trachea and removing the sternum, in the 
case where the pericardium was spoken of as filled, and is 
drawn directly from the cadaver. The exact amount which 
must be injected before an increase of vertical flatness is 
obtained, I have not yet determined. It may be objected, 
that the fluid was introduced at the bottom of the pericar- 
dium, while naturally it should start at the base of the heart. 
In my earlier experiments I did introduce the fluid where 
the pericardium is reflected over the great vessels, but even 
when it was in very small amount and quite insufficient to 
cause any increase of percussion flatness, it immediately ran 
down the side of the heart to the bottom of the pericardium, 
so that I cannot conceive of its collecting to any appreciable 
amount at the base of the heart and being retained there. DIAGNOSTIC OF PERICARDIAL EFFUSION. 
15 
Even if it was retained there, it would not by its form re- 
present an inverted triangle, as I have proved by inverting 
the cadaver and filling the upper part of the pericardium, 
when the resulting cast always had its broadest part directed 
towards the diaphragm. Nevertheless, as the convictions 
of some of the greatest clinical observers on this point are 
very decided, we must, in deference to their opinion, wait 
until more extended clinical facts are brought to bear on the 
subject, before eliminating flatness at the base of the heart 
as diagnostic of the early stage of effusion in pericarditis. 
As to the change of the position of the heart’s apex 
spoken of by Flint and Reynolds, namely, that the apex is 
pushed upwards and outwards by a moderate effusion, so 
that the impulse appears in the fourth left intercostal space, 
I did not in my experiments find that this was the case, the 
apex being found by measurement to remain in its normal 
position ; and in fact it seems highly improbable that a fluid, 
which according to Skoda always has a smaller specific 
gravity than the heart, should push that organ upward, a 
proceeding which would be quite contrary to the physical 
laws which govern the relation between a solid body and a 
liquid, when such body is suspended in the liquid and has a 
greater specific gravity than the liquid, lly referring to 
Diagram III.—of the small effusion—it seems more plausi- 
ble to account for the pulsation in the fourth interspace, by 
the tumultuous action of the side of the heart, which, as is 
seen in Diagram III., can approach the thoracic wall at this 
point, especially as it has been observed by Professors 
Ludwig and Ilowditch that the impulse of the heart, as 
seen normally in the fifth left intercostal space, need not 
necessarily be caused by the heart’s apex, but by a portion 
of the heart above the apex striking against the thoracic 
wall. 
The whole question, however, depends on the correctness 
of Skoda’s observation, that the heart must always sink in 16 
ABSENCE OF RESONANCE, ETC. 
a pericardial effusion as far as its attachments will allow, 
and this can only be determined by carefully taking the 
specific gravity of pericardial effusions of different densities 
and comparing them with the specific gravities of the fluids 
in which the suspended heart will float or sink. Skoda, 
however, is also incorrect in supposing that the small 
amount of fluid stands as high as possible in the pericardium, 
thus causing an increased vertical flatness, for in reality the 
lower part of the pericardium envelopes the lower part of 
the heart so loosely that the small effusion has plenty of 
room to collect in the lower part of the pericardium first, 
making an increased distension in breadth, and, as we have 
seen, appearing in the fifth interspace. 
Before proceeding to discuss the general conclusions which 
wre are warranted in assuming in regard to the diagnosis of 
pericardial effusion, we must consider what changes in the 
praecordial area of flatness may be due to changes in the 
heart itself. 
For this purpose, it is not necessary for us to consider 
particularly whether the left or right side of the heart is 
hypertrophied or dilated : the question of interest to us, in 
this connection, is the result of all these conditions, that is, 
simply what possible part of the pr&cordia may be rendered 
flat on percussion by an enlarged heart; for I hold that we 
cannot as yet distinguish with sufficient certainty between 
the absence of resonance obtained on percussing over a fluid, 
from that obtained on percussing over a solid organ, such 
as the heart or liver, to warrant us in giving an opinion as 
to which is fluid and which is solid, and that therefore it is 
of the utmost importance to determine where the heart, if 
enlarged, might cause flatness, for this area must be taken 
into consideration, and subtracted from the whole area of 
flatness, before we are are justified in introducing a trocar 
expecting to find fluid. DIAGNOSTIC OF PERICARDIAL EFFUSION. 
17 
In determining the possible area of percussion flatness 
caused by enlargement of the heart, I have consulted Bam- 
berger, Oppolzer, Gerhardt, Shroetter, Paul and Felix 
Niemeyer, and finally Professor Adolf Weil, of Heidelberg, 
who has published some excellent plates on this subject. 
These authors all concur as to the extension of the flatness 
to the left of the left nipple, just as we have seen the effusion 
to extend. Oppolzer and Gerhardt speak of the possible 
increase of flatness upwards beyond the line of the fourth 
rib. 
There is some difference of opinion as to the extension of 
the flatness to the right of the sternum. Shroetter contends 
that increase of flatness to the right of the sternum as 
diagnostic of enlarged heart is not nearly so frequent as is 
generally supposed, and gives as an instance of great in- 
crease in size two to five centimetres to the left of the left 
mammary line, and possibly two to four centimetres beyond 
the right edge of the sternum. Professor Ellis doubts if we 
ever find flatness beyond the right edge of the sternum, and 
say* that it would be especially rare as low as the fifth inter- 
space. Oppolzer says that the flatness may possibly reach 
one centimetre beyond the right edge of the sternum : the 
other authors either give the right edge of the sternum as the 
limit, or do not state definitely the part of the sternum 
where the flatness passes to the right. Weil holds that, even 
in extreme cases, the absolute dulness or flatness does not 
encroach on the fifth right intercostal space, while the rela- 
tive dulness may extend over the right edge of the sternum 
for from two to three centimetres. The area of flatness of an 
enlarged heart represented in Diagram VI., gives the com- 
bined views of these authors, to even an exaggerated 
degree, so as to avoid all error, and it will be seen that the 
area of flatness, represented by A, does not enter, to any 
appreciable degree, the fifth right intercostal space. 18 
ABSENCE OF RESONANCE, ETC. 
All these authors consider that the form of the area of 
flatness of an enlarged heart is determined by the retracted 
border of the lungs. 
Oppolzer and Kunze And that, in enlargement of the 
whole heart, a truncated triangle form of flatness is some- 
times found. Weil also, in his plates, makes the area of 
flatness of an enlarged heart have a triangular shape. Ac- 
cording to these authors’ own testimony, then, we cannot 
consider the triangular or truncated pyramid form of the 
prrccordial area of flatness decidedly characteristic of effu- 
sion, for both the normal and enlarged heart may assume 
these shapes. 
On precise experiment, also, we find that the form of the 
area of flatness merits the name of a semicircle in the small 
effusion rather than a triangle or pyramid, and that the 
latter terms certainly would be misleading if applied to the 
large effusion as represented in Diagram V. Why then 
retain these misleading terms, which only tend to confuse us 
in our endeavors to properly appreciate the subject? 
As, however, the effusion, as it varies in its amount \yill 
also vary in its form, it is wiser in making our diagnosis by 
percussion, not to seek for any particular shape, but to find 
a part of the thorax where flatness on percussion will be 
significant of effusion. Now the flatness found to the left 
of the sternum, that found in the vertical line, and possibly 
that found to the right of the sternum above the fifth rib, may 
occur and yet no effusion be present; we therefore eliminate 
all that area of flatness marked in Diagram VI., area A, and 
find that we have left, in both the small and large effusion, 
an area of fatness in the fifth right intercostal space, as 
represented in Diagram III. In this interspace the flatness 
first appears as characteristic of effusion. It probably also 
appears, at the same time, to the left of the sternum, but 
the physiological flatness of the heart here obscures it. For 
diagnosis, flatness, at from two to three centimetres DIAGNOSTIC OF TEItlCARDIAL EFFUSION. 
19 
from the right edge of the sternum in the fifth intercostal 
space, would be almost absolutely sufficient to mark the 
presence of an effusion, unless the opinions of authorities, 
on enlarged heart, are proved to be incorrect; and I would 
here merely suggest, as it is a subject which I expect to 
treat of in a future paper, that puncture of the pericardium 
can safely be performed in the fifth right intercostal space, 
at from four and a half to five centimetres from the edge of 
the sternum, where the flatness, as is shown in Diagram III., 
extends even beyond the line E E' E'', which represents, in 
Diagram VI., the relative dulness of the enlarged heart, 
according to Weil. At least it will be far safer, so far as 
the heart is concerned, to perform paracentesis at this point, 
than where it has been heretofore advised and practised by 
surgeons, namely, in the third, fourth and fifth left interspaces ; 
for, as is seen in Diagram III., we may, in the third and 
fourth spaces, have our flatness caused by the physiological 
flatness of the heart, and by referring to the casts of cocoa 
butter, which I have preserved, we find that the layer of 
fluid, even when present, is thinnest over that portion of the 
prtccordia and also in the part which corresponds to the fifth 
left interspace, while it is thickest at the sides. 
There are a few points which it will be well to speak of 
here. 
The lung seems to retract before the fluid, and it is the 
lowest part of the lung which first retracts, thus leaving a 
curved line of flatness with its convexity outwards. 
The top of the area of flatness is almost on a line with 
the broadest diameter of a small effusion, as is seen by 
comparing Diagrams III. and IV. 
Additional value is given to the diagnosis of an effusion 
by percussion, from the facts, that where an effusion is 
present, the friction sound need not necessarily have ever 
occurred ; that the apex beat in effusion may be felt to the 
left and below the nipple, as in enlarged heart, extending 20 
ABSENCE OF RESONANCE, ETC. 
outwards as far as the line of flatness does, and vice versa ; 
that at times the apex beat of an enlarged heart may be very 
feeble, and even imperceptible; also, that the rational signs 
of enlarged heart and pericardial effusion may be at times 
almost identical. 
In conclusion, I shall describe as briefly as possible the 
extremely small number of clinical observations which I 
have been able to make during the past winter. 
The first was a woman who died at the Channing Home. 
Flatness on percussion was found in the fifth right intercostal 
space to the distance of five centimetres from the edge of 
the sternum. There was no increase of vertical flatness. 
The autopsy showed the pericardium to be distended with 
about one hundred and twenty cubic centimetres of fluid. 
The second case is especially interesting, as showing the 
difficulty which may be met with in the differential diagnosis 
between enlarged heart and effusion, without the aid of our 
fifth right intercostal space. This case, a boy six years 
of age, is best spoken of in connection with another, a girl 
eleven years of age, who was under observation at the same 
time, through the kindness of Dr. Davenport of the Child- 
ren’s Hospital. In both patients the same rational signs 
were presented, such as orthopncea, pracordial pain, etc. 
In both cases the attack followed acute articular rheumatism. 
In both cases the force of the heart’s impulse was of about 
the same intensity, and appeared to be a little to the left, 
and below the left nipple. The vertical flatness was not 
increased in either case; the area of flatness to the left of 
the sternum was identical in both cases. In the boy, how- 
ever, flatness was found in the fifth right intercostal space, 
while in the girl it did not extend beyond the left edge of 
the sternum. In the boy a loud undoubted pericardial 
friction sound developed at the base of the sternum ; in the 
girl a decided murmur developed at the apex of the heart. 
These last two symptoms are spoken of to show the strong DIAGNOSTIC OF PERICARDIAL EFFUSION. 
21 
probability of the correctness of the diagnosis that the boy 
was a case of pericarditis, and that the girl was a case of 
endocarditis with enlarged heart, though of course this could 
only be proved by autopsy, and the cases must merely be 
taken for what they are worth ; but, when we remember 
that the friction sound might have been absent, and that 
apparently endocardial murmurs may occur, where no disease 
of the heart itself, but merely a pericardial effusion is pre- 
sent, we again have to appeal to our fifth right interspace 
for diagnosis. 
My third and last case was a patient seen at the City 
Hospital, whom, through the kindness of Dr. Doe, I was 
allowed to thoroughly examine. In this patient the area of 
percussion flatness verified by Dr. Doe, exactly corresponded 
to that marked out in Diagram III., and I made mv 
nosis simply by the flatness in the fifth right interspace. 
The case was especially interesting from the fact that it 
illustrated Gerhardt’s observation of the change of the area 
of flatness in effusion on change of position of the patient. 
When the patient was in the position of ortliopnoea, we 
obtained the fifth interspace flatness ; when she was horizon- 
tal, this flatness disappeared, leaving the normal resonance 
of the lung. 
As additional proof that this was a case of pericardial 
effusion, an undoubted pericardial friction sound, testified to 
by several of the physicians at the Hospital, developed, and 
according to Professor Traube it is exceedingly rare to 
mistake this sound for a pleural friction sound. DIAGRAM I. 
Normal Thorax. 
Up A—Physiological area of percussion flatness of the heart on expiration. 
H B—Liver. 
0 B —That portion of the liver which is covered by the right lung. 
PI C— Lung. 
S—Sternum. 
—Nipple. 
1,2, 3, 4, 5, 6—Ribs. 
Broken line—Border of lung. DIAGRAM II. 
The Lungs have been Removed. 
M k—Normal shape of the heart in its pericardium. 
ill B —Liver. 
IB D—Effusion. 
AfD—The shape which the pericardium resumed, in a case where consider 
able fluid had been introduced into the sack. 
S—Sternum. 
(^—Nipple. 
1,2,3, 4, 5. 6—Ribs. A Small Amount of Liquid has bekn Introduced into the Sack. 
DIAGRAM III. 
fUj A —Tlie portion of the area of flatness which is still caused by the physio 
logical flatness of the heart. 
HI B— Liver. 
B1 B —That portion of the liver which is covered by the right lung. 
[sj C—Lung. 
IB D —Effusion. 
A-j-D—Area of percussion flatness found when the effusion is small. 
S—Sternum. 
(ip —Nipple. 
1, 2, 3, 4,5, 6—Ribs. 
Broken line—Border of dung. DIAGRAM IV. 
Represents Diagram III. with the Lungs Removed. 
Hf! A—a portion of the normal heart enclosed in the pericardium. 
ill B —Liver. 
HI D—Effusion as it appeared in the sack, the cocoa butter being in small 
amount, and the lungs having been removed, after the butter had 
hardened. 
S—Sternum. 
@) —Nipple. 
1,2, 3, 4, 5, 6—Ribs. DIAGRAM V. 
A Large Amount of Liquid has been Introduced into the Sack. 
H B —Liver. 
H B —That portion of the liver which is covered by the right lung. 
C —Lung. 
fj§ p —The area of percussion flatness caused by a large effusion. 
S—Sternum. 
(§) -Nipple. 
1,2, 3, 4,5, 6—Ribs. 
— Broken line—Border of lung. DIAGRAM VI. 
Enlarged Heart. 
H A.—Area of percussion flatness caused by an enlarged heart. 
B B— Liver. 
HH B —That portion of the liver which is covered by the right lung. 
EI3 C —Lung. 
E E'E"—The line marking the area of relative dulness of the enlarged heart. 
S—Sternum. 
@)—Nipple. 
1,2, 3, 4, 5, 6—Ribs. 
Broken line—Border of lung.