{686} sometimes temporarily relieves the dyspnoea. On this basis
Dickenson and Fagge and other English writers recommend venesection for
the relief of the pulmonary engorgement or heart-failure. Pain in the
præcordial region which accompanies valvular insufficiency may
sometimes be relieved by the application of leeches over the præcordial
space. Hyoscyamus, hydrochlorate of morphia, nitrate of amyl,
chloroform, and a belladonna plaster over the præcordial space have all
been employed for the same purpose.
It is to be remembered that such pain is the cry of the heart-muscle
for a higher degree of nutrition.
Bleeding in heart disease favors dropsy by thinning the blood and by
diminishing the heart-power. It should never be resorted to except in
great emergencies. Niemeyer advises arsenic and antimony in mitral
valvular disease, but does not say in what cases or for what reason
they are to be used. When in the late stages of mitral disease the free
use of digitalis fails to regulate the pulse and to relieve the
pulmonary engorgement, its prolonged administration does harm rather
than good; but in every case of mitral disease where the drug has not
been used it may be safely affirmed that its administration will give
prompt relief.
If it becomes necessary to use an anodyne or hypnotic at any period in
the course of mitral valvular disease, morphia hypodermically is to be
preferred to all others.
The rules in regard to hygiene, diet, and exercise which have been
given for the management of mitral disease are equally indicated in the
management of pulmonary obstruction or regurgitation. Beyond this their
treatment is purely symptomatic.
The treatment of tricuspid obstruction depends upon the gravity and
sequelæ of the accompanying disease--viz. mitral. Stenosis of the
tricuspid orifice never occurs until mitral obstruction is excessive,
and the latter condition is always the predominant one.
The same rules of hygiene and diet which have already been given for
mitral disease must be followed with the utmost care by those suffering
from tricuspid reflux. The patient must lead a life of perfect quiet,
and should live in a warm, equable climate. When occurring with mitral
disease digitalis should not be omitted; for although the drug, by
increasing the action of the heart, would seem to be injurious, yet it
promotes ventricular contraction, and thus tends to relieve the
tricuspid pressure. In tricuspid insufficiency with pulmonary emphysema
this drug should be very cautiously exhibited, and its use or omission
must depend upon the effects produced in each case. If the cerebral
symptoms are exaggerated, it must be discontinued. The indications for
the use of tonics, such as iron, quinine, strychnine, are the same and
follow the same demands as in mitral disease. When venous engorgement
demands prompt relief, drastic cathartics or the abstraction of a few
ounces of blood from the arm will temporarily diminish the high venous
tension. The treatment of the dropsy and the local oedema is the same
as for similar condition occurring in mitral disease. There are many
subsidiary remedies which will have to be employed for the relief of
gastric, hepatic, and intestinal symptoms, which are often the most
troublesome occurrences of this disease.
{687}
CYANOSIS AND CONGENITAL ANOMALIES OF THE HEART AND GREAT VESSELS.
BY MORRIS LONGSTRETH, M.D.
The questions involved in the subject of the congenital defects of the
heart and its great vessels and their causes are not easy of
settlement. In the first place, the seat, the extent, and the
consequences of the deficiency or defect are not regular or constant.
Secondly, the causes and the mode and date of their origin are involved
in great obscurity. Their classification either on a purely
topographical or on a purely etiological basis is almost impossible on
the one hand, because the changes are so irregular and varying, and, on
the other hand, because our knowledge of the primary cause or causes of
the alterations is quite defective. The views which at the present time
find most favor arrange the various malformations into classes
according to the period of development of the foetus at which the
arrest or change of tissue occurred--as it were, a chronological
classification. The ideas in respect to the pathology or the
pathological causes of malformed hearts have undergone great
changes--changing in some degree pari passu with the mode of
classification, and in great degree inducing and compelling such
changes.
In early times deformed hearts were looked upon as monsters,
curiosities, lusus naturæ. When a knowledge of foetal development and
circulation was acquired the deformed heart was compared with the
heart-formation in classes of a lower grade than mammals. Such were the
beliefs of comparative anatomy and physiology that it was held that the
human foetus was matured by stages from the forms found in the lowest
invertebrates through the various ascending scales of the animal
kingdom. This classification was, on the basis of comparative anatomy,
purely anatomical. The underlying thought of such pathological teaching
was that in the original ovum something was left out--an actual
deficiency of parts which, when developed in the natural manner, made
man different from the lower animals; or else, supposing these parts to
have been originally present, there was a defect of plasticity, causing
a failure of the proper adhesion of symmetrical portions. Excessive
development was looked upon as a surplus of parts in the ovum, and by
their growth certain of the openings of the heart were prematurely
closed. In this view of the pathological alterations no expression of
opinion was made how the excess or deficiency of structure was
occasioned: the malformation was merely a failure of the parts to rise
and pass through the various grades of development--a too rapid or a
too slow growth of one or more of the various parts of the foetal
heart. There was no reason assigned why the human ovum had in it
deficiencies or excesses of material, and thus came to resemble in one
of its parts the conditions found in lower animals.
About 1850, Dittrich of Erlangen, by his studies of inflammation of the
heart during intra-uterine life, quite diverted public opinion from the
older views of the subject. Peacock's earlier studies preceded this
work by a few {688} years, and a few years later came Meyer,[1] who
greatly extended the scope and influence of the inflammatory theory of
Dittrich. Ten years later commenced the clinical recognition of
congenital heart defects, and especially the anatomical changes in
congenital narrowing of the pulmonary artery, by Von Dusch and by
Mannkopff,[2] and by Stoelker.[3] Friedberg had, however, as early as
1844, published his studies of the stages of development of the
circulatory organs in the human embryo, and had in accordance therewith
divided the malformation of the heart into three groups, corresponding
to the three periods of the heart's growth. This was the classification
adopted quite independently by Peacock of London in his first
publication in 1857. It was not until after Dittrich's studies[4] and
Meyer's that any distinctive cause was assigned for the failure to
develop.
[Footnote 1: _Virch. Arch._, Bd. xii., 1857.]
[Footnote 2: _Ann. des Charité-Krankenh. zu Berl._, 1863.]
[Footnote 3: _Diss._, Bern, 1865.]
[Footnote 4: See Dorsch's (his student) dissertation, _Die
Herzmuskelentzundung als Ursache angeborner Herzcyanose_, Erlangen,
1855.]
Carl Heine,[5] and also Halbertsma, proposed a classification based on
the quantitative and qualitative differences. Under the first division
the former placed such changes as absence of the heart, deficiency of
individual parts, abnormal smallness, atresia, and fissures; and, in
the other direction, duplication of the heart as a whole or in its
individual parts, and abnormal largeness. The qualitative differences
were deviations of form, of position, and of the arrangement of the
great vessels.
[Footnote 5: _Angeborene Atresie d. Ostium arteriosum dextrum, Beitrag
z. Lehre v. d. angeborenen Herzanomalium_, Tübingen, 1861.]
Peacock's classification in his earlier edition (1858) was partly on
the basis of the time at which arrest of development occurs, and partly
on the degree of impediment to the circulation and the functions of the
heart. In his second edition he adheres to the same classes, with
slight modifications, thus: 1. Arrest of development early in foetal
life (fourth to sixth week; heart with two or three cavities; single or
imperfectly divided arterial trunk); 2. Arrests at a later period
(sixth to twelfth week; imperfect auricular or ventricular septa;
imperfect or misplaced vessels); 3. Those after the third foetal month
(closure and patency of foetal passages; irregularities of valves,
cavities, etc.).
Kussmaul (1865) published a very important work on malformations due to
defects of the pulmonary artery,[6] and these malformations he
considers under two general groups--viz. those having their origin
before the ventricular septum closes, and those occurring after this
period. His most valuable contribution to the subject is the importance
which attaches to the distinction between primary and secondary defects
or arrests of development--_i.e._ between an original alteration of
growth or morbid condition, and those which follow from it as a
necessary consequence. Of his classification, and of the importance of
pulmonary artery malformations, a further description will be given.
[Footnote 6: _Ueber angeborene Enge und Verschluss der
Lungenarterienbahn_, Freiburg, i. B.]
For study, one would wish to arrange the malformations in classes
convenient for clinical purposes. For example, separate them into
groups of the defects compatible with extra-uterine existence and those
incompatible with adult life. Unfortunately, this division is not
possible. We find many cases of defects involving originally the same
seat: in one the individual lives many years, in another the
obstruction immediately induces symptoms, and death soon comes. A
classification according to the seat of the disease alone, if it could
be made, would give the subject a simplicity equal to that of valvular
heart disease in the adult. Here, however, we find such variations in
the details of the alteration that if this principle of classification
alone is {689} employed the confusion becomes very great. It would
seem, therefore, that the principle first made use of by Kussmaul, of
classifying the defects by distinguishing the primary malformations
from their secondary effects, renders the subject the most simple, and
at the same time affords the advantage of more readily understanding
the mechanism of their production.
It will be useful to pass over seriatim, following the course of the
foetal circulation, the various valves, orifices, and foetal openings
to be able to comprehend which are most liable to defects or to see
which defects most frequently occur, and also to find which alterations
produce the greatest disturbance of the circulation.
1. The Foramen Ovale and Septum of the Auricles.--In markedly deformed
hearts the entire septum may be in greater or less degree wanting, as
seen in cases of the bilocular or trilocular organ. This defect is
comparatively rare, and the foetus has but a short extra-uterine life.
In other cases the septum is complete, but the foramen may be unusually
large, and remain unclosed wholly or in part; perforations may be
present, or the valve may merely fail to adhere. Of the latter cases,
the patent foramen is found in conjunction with defects at other parts,
while small sieve-like perforations or the mere non-adherence of the
membrane--both of very common occurrence--may be owing to a temporary
obstruction during the early hours of life or to any unknown cause, or
may possibly be due to a reopening of the foramen from an acquired
disturbance of the circulation. Opinions vary as to the mechanism of
the closure of the foramen. Some consider it a passive process due to
increased blood-pressure in the left auricle, coming from the entrance
of the current of aërated blood from the lungs; others speak of it as
an active process resulting from the excitation to contraction of the
muscular fibres in the membranous valve. Whatever may be the mechanism,
patency of the foramen ovale of undoubted foetal origin (excepting the
minute perforations and oblique slits) must be looked upon in nearly
every case as a secondary defect--secondary to an obstruction to the
outflow of blood from the ventricles through the great arterial trunks,
or it may be from the auricle itself through defect of the
auriculo-ventricular orifice. In a vastly preponderating number of
cases it results from pulmonary artery obstruction. The foramen may
close, however, in such a case if an outlet is provided by the aorta
through an open septum ventriculorum, or when this vessel arises from
both ventricles. Narrowing or closure of the right auriculo-ventricular
orifice, as a primary cause, can prevent the closure of the foramen
ovale; primary narrowing of the tricuspid orifice is very rare, single
or combined with other defects. In these cases the direction of the
blood is from the right auricle to the left. There are, however, cases
on record of patency of the foramen ovale in which the blood-current is
from the left to right side, the reverse of the foetal course. Here the
cause to be looked to is a congenital deficiency of the mitral orifice,
or a narrowing, closure, or malposition of the aorta.
2. The Right Auriculo-ventricular Orifice and Tricuspid Valve.--A
primary deficiency of this orifice and the valve guarding it very
rarely occurs as a primary defect and uncombined with malformation of
other parts of the pulmonary circulation. It does come in certain cases
in conjunction with great narrowing of the pulmonary orifice or artery,
but by no means commonly. If the pulmonary outlet is normal and in the
usual position, the right auriculo-ventricular orifice is never found
closed, although the leaflets have been seen defective, permitting
regurgitation. In certain other cases the orifice and valve, as well as
entire right ventricle, show a failure to develop, and all these parts
appear shrivelled. This condition is a secondary result, due to a great
deficiency of the pulmonary artery and narrowing of the pulmonary
conus. The malformation of the pulmonary artery in such cases results
from an unequal division of the truncus communis--the narrowing {690}
of the conus generally from endo-myocarditis. The aorta is unusually
large in diameter. The blood from the right auricle passes through the
foramen ovale to the left side of the heart; the ductus arteriosus
Botalli remains open, or in very rare cases the mixed venous blood
reaches the lung through collateral channels. In rare cases the blood,
in addition to the open foramen ovale, has a direct passage from the
right auricle into the left ventricle.
3. The Pulmonary Artery and the Right Conus Arteriosus.--This situation
presents by far the largest number of cases of congenital heart
malformation of primary occurrence. The defects at this part require
different interpretations according as they are found within the right
ventricle or in the pulmonary artery itself. So frequent are the
defects at these seats that Kussmaul bases his classification, for a
large proportion of cases, on the malformation of the pulmonary artery
track, and describes them as combined with defects secondarily
resulting in other parts.
The narrowing or closure may exist either at the limit between the
sinus and the conus of the right ventricle, the conus arteriosus may be
uniformly narrowed, or the defective development may involve the
orifice only or the whole length of the pulmonary artery. Many of these
defects, resulting in closure or narrowing, are due, as Rokitansky was
the first to show, to inflammatory changes. It is Kussmaul's great
merit to have pointed to the fact that a very large proportion of all
malformations owe their origin primarily to diseased conditions
originating at this seat. The varieties of these defects and their
secondary consequents will be described later.
4. Patency of the Septum Ventriculorum.--The degree of deficiency of
the septum varies greatly. The entire partition between the ventricles
may be wanting or exist in merely a rudimentary condition. Ordinarily,
there is found a triangular, rounded, or oval opening in the septum
close to the base of the heart, at the portion which in the normal
heart consists of only a membrane (pars membranacea). Besides this
usual opening, one, or even two, others may present themselves at other
points of the septum, thus forming multiple communications between the
cavities. In narrowing or closure of the pulmonary passage the septum
is more or less deflected toward the left ventricle to allow a freer
passage of blood from the right side of the heart through the open
septum into the aorta. In other cases the passage of blood may be from
the left ventricle into the right--the reverse of the usual direction.
The defects of the septum are usually of a secondary character,
dependent on primary malformation of other parts, and, as already said,
chiefly those of the pulmonary track. They are of congenital origin,
commencing early in foetal life, before the third month, when normally
the septum closes. Hence patency of this septum furnishes in many cases
a valuable means of determining the date of the primary defects with
which it is found combined. This malformation, however, does very
rarely stand as an isolated defect, and still more rarely it is
believed to have been acquired through an ulcerative destruction
(myocarditis) of a portion of the septum, either during foetal or
extra-uterine life; wasting or atrophy of the membranous part is
sometimes thought to have occurred. In these latter cases a
misdirection of the blood-current of a marked sort rarely occurs unless
the inflammatory or other changes affect the main arterial orifices.
5. The aortic and mitral orifices are very much less frequently found
narrowed or obstructed as the result of congenital primary defects than
the orifices and their valvular apparatus of the right heart; and, also
following the rule which obtains on the right side, the mitral is less
frequently affected than the aortic orifice.
6. Of the Malformations of the Great Vessels.--Such changes may come
alone, though usually they are combined with simultaneous or
consecutive defects in other parts of the central circulatory
apparatus. Of the sorts of {691} defects or malformation which these
two vessels suffer, there are two chief forms to be described: 1, such
as result from an unequal division of the vessels in their formation
from the truncus communis; 2, those which result in more or less
complete transposition of their origins. Of the transpositions we may
find two sorts: in one the vessels maintain nearly their normal
relative positions to each other, but each communicates with the
improper ventricle; in the other they are transposed relatively to each
other and also to the respective ventricles. In the first of these
classes, unequal division, one variety may be ascribed to a defective
or irregular development of the septum by which the vessels are formed
of unequal sizes; the other, originating later in foetal life--_i.e._
after the third month (for the septum between the vessels is completed
nearly simultaneously to the ventricular septum)--results from
inflammatory or other morbid change in or about the orifice and trunk
of one or other vessel, causing a narrowing or closure, the other
vessel showing compensatory enlargement. This form is not a true
unequal division of vessels. The apparent origin of one or both vessels
from the same ventricle in these cases is not a true example of
transposition of the vessel, but is due to a deviation of the septum
ventriculorum toward one side or the other from increased blood in the
ventricle from which the outflow is more or less completely obstructed.
True transpositions of the vessels, both relatively to each other as
well as to the ventricles, originate very early in foetal life, and
these as well as the unequally-divided vessels are primary defects, and
are usually accompanied by many secondary changes. Another malformation
occasionally found, involving the beginning portion of the great
vessels, is a failure of complete division: the septum truncus communis
remains rudimentary, and the blood of the aorta is free to mingle with
that in the pulmonary artery. This defect may be accompanied with a
rudimentary septum ventriculorum.
7. Ductus Arteriosus Botalli.--This foetal orifice varies greatly in
the conditions which are presented; sometimes it is entirely wanting,
in others patulous and even in a state of dilatation; in others, again,
a short portion is patent (this state is probably comparable to failure
to adhere seen in the valve of the foramen ovale or the sieve-like
opening in the fossa ovalis; unlike the valve of the foramen, the
ductus probably never reopens), or in yet others the ductus is closed
in some cases of malformation, and in others of very similar character
it remains open. It becomes difficult to explain the varied states of
the duct, so dissimilar are they to other defects of development
present. In none of the conditions which are presented can the
malformations be regarded as of a primary character. Our surprise at
certain of its conditions probably must depend on a failure to justly
appreciate the primary malformation present, or else on changes in the
heart and the circulation coming at a period subsequent to the date of
origin of the malformation of the duct itself. When the duct is open at
one end and closed at the other, the open part communicates usually
with the pulmonary artery, since the closing process commences normally
at the aortic extremity: the closure beginning at the pulmonic
extremity is occasionally seen in malformations of heart where the
blood-current has had a reverse direction through the duct.
The premature closure of the ductus arteriosus Botalli, which is spoken
of by some authors, seems to be a rather unfair designation to apply to
the condition. In most cases it is in reality an absence of the duct
dependent on the defective development of certain of the branchial
arches. In other cases the apparent premature closure is due to general
uniform narrowing, almost closure, of the pulmonary orifice and
vessels; in such cases the lungs are supplied by the enlarged bronchial
arteries or other collateral branches. The ductus arteriosus Botalli
remains patulous when the pulmonary artery is {692} narrowed or closed;
in these cases the blood from the right side of the heart to reach the
lungs must pass either through an opening in the septum ventriculorum
or through the patent foramen ovale. The duct is generally open in
cases of transposition of the main arteries, or even in cases of
obstruction of the aortic orifice, or of uniform narrowing of the
descending aorta or its main branches. Its usual length and its point
of origin from the pulmonary artery or its branches, as well as its
junction with the aorta, may vary. Two ducts have been found--one from
each pulmonary branch, one of them joining the aorta as usual, the
other seeking one of its branches. A distinct duct has been found
arising directly from the right ventricle. None of these defects are to
be considered as primary malformation, but as the secondary results
from alterations of the circulation occasioned by other malformations
of the heart or of its great vascular trunks.
* * * * *