HEART DISEASES IN PREGNANCY
Over 20,000 women die in childbirth each year in the United States,
and about 100,000 infants, and more or less permanent injury from
parturition is almost general in mothers. The mortality in the
trenches during the present great war is 2 per cent.; the mortality
of infants during the first year is 14 per cent. Very much of this
mortality and invalidism is attributable to lack of skill in the
licensed unfit. We commonly deem parturition merely a physiological
process, and for that reason the state permits ignorant midwives and
quacks to take upon themselves with impunity the responsibility and
the risks of delivery.
It is difficult to draw the line between normal and abnormal
parturition, but every labor, as women now are in civilized
countries, should be regarded as a grave surgical operation, and
the indications that must be met in a surgical operation are likely
to occur in almost any parturition. The strength of the patient,
the condition of the heart, lungs, kidneys, and blood, sepsis and
antisepsis, the nature and technic of the various operations that
may be required, and the complications that may arise, are all to be
understood and met conscientiously. No physician who has any regard
for morality and his own reputation now will accept an obstetrical
case unless he has had the woman under frequent observation for
months before delivery. If the mother or child dies because of the
bungling or surgical uncleanness of the physician or midwife,--and
unfortunately such deaths occur almost hourly,--this physician or
midwife is guilty of murder. There may be an abnormality of the
uterine or abdominal muscles used in parturition, a disproportion
between the parturient canal and the child, or various accidents
of labor; and these conditions are so frequent in occurrence and
so grave that their removal requires great medical skill, fine
discernment, quick and exact judgment, and often decidedly courageous
purpose.
New methods of treatment frequently appear, and the quack is likely
to be among the first by which the new is tried. The use and abuse
of pituitrin is an example of such a method. About 1909, pituitary
extract as a uterine stimulant was first described and it was
immediately taken up by competent men and more frequently, perhaps,
by the quack. The extract is from the posterior lobe of the pituitary
gland, and when injected subcutaneously or into a muscle it is a very
powerful oxytocic. In a few minutes the injection markedly increases
the intensity and duration of the pains. The effect lasts for an
hour or an hour and a half. Whitridge Williams[129] says a judicious
administration of the drug will do away with the use of low forceps
in from one-third to one-half of the cases, but its ignorant use
places the life of the mother and child in jeopardy. Mundell[130]
found twelve cases of rupture of the uterus, thirty-four cases of
fetal death, and forty-one cases of fetal asphyxia pallida in which
resuscitation was effected only after prolonged and vigorous efforts,
sometimes for over an hour.
[129] _Obstetrics_, 4th ed. New York, 1917.
[130] _Jour. Amer. Med. Assoc._, June 2, 1917.
If there is any serious obstacle at all to delivery in the parturient
canal or in the fetal position, or the like, pituitrin is likely to
cause rupture of the uterus and asphyxiation of the child. It should
never be used when there is the slightest danger of rupture of the
uterus; or when the child is suffering; or in a shoulder and most
pelvic presentations; or in elderly primiparae with rigid muscles;
or when the cervix is not fully dilated, lest the undilated cervix
be torn off; or where there is inertia after prolonged effort to
overcome an obstacle to delivery. It is never to be used in a normal
delivery merely to hasten the birth. Obstetrical cases are tedious,
and an impatient physician with an atonic conscience is likely to use
pituitrin so that he can get back to his bed.
Comparisons between the fetal mortality after the use of pituitrin
or the forceps are erroneous. Quigley[131] contrasted the fetal
mortality in these conditions. In 147 pituitrin cases it was 2.7 per
cent., in about five or six times the number of forceps cases it
varied from 5.7 to 15.63 per cent.; but wherever there is any real
need at all for the forceps, pituitrin at once is contraindicated
except in easy low forceps deliveries, where in the hands of a
skilled man pituitrin may safely replace the forceps to avoid
possible instrumental infection of the uterus. There are contractions
of the uterus toward the end of gestation, before labor proper sets
in, which cause what are called False Pains, and these must not be
mistaken for the beginning of labor, as unnecessary examinations
and meddlesome interference may bring on great harm. Uterine atony,
or weak pains, may affect the patient in the first stage of labor,
in which the cervix of the uterus should be dilated; or the second
stage, in which the child is delivered; or the third stage, the
post-partum period, when the placenta is thrown off. Contractions
of the uterine muscle cause pain, and these contractions themselves
are called the Pains. In the first stage weak pains may prolong the
dilatation of the cervix for days and expose the mother to sepsis or
exhaustion, and the child to consequent danger.
[131] _Jour. Amer. Med. Assoc._, April 10, 1915.
In the second stage the abdominal muscles, which push the child
out of the uterus, fail to work if the pains are weak. Causes of
unsuccessful pains in the second stage are: an infantile uterus,
fibroids or other tumors in or near the uterus, peritoneal adhesions,
a full rectum or bladder, abnormal position of the uterus, a
pendulous abdomen, diseases of the uterine wall, scars from past
operations, chronic metritis or endometritis, primiparity in
relatively advanced age, twins, distention of the bag of waters, gas
in the uterus, abnormal position of the child, contracted pelvis,
adhesions of the membranes about the os uteri, fatigue of the woman,
and tetany or stricture of the uterus. The obstetrician must be able
to diagnose the special cause and treat the indications.
One of the causes of weak pains is a diseased heart. Systolic murmurs
at the base of the heart and an accentuated second aortic sound
are quite common in pregnancy and may not be of grave importance.
If there is a genuine cardiac lesion with good compensation, the
labor is usually successful and without notable damage to the
woman, although obstetricians like De Lee think that such patients
appear to develop decompensation sooner than do women who are
not pregnant. If the heart disease is advanced and the heart is
in unstable equilibrium, especially if there is myocarditis or
fatty degeneration, the heart is likely to break down in pregnancy
or labor. In chronic cardiac lesions, pregnancy, through venous
congestion, tends to renal and hepatic disturbance, or to dyspnoea
and carbonic acid narcosis. The uplifting of the diaphragm by the
enlarged uterus increases the respiratory difficulty. There may
be edema of the lungs, hypostatic pneumonia, dropsy, insomnia,
albuminuria, and other serious symptoms.
During labor a diseased heart may fail and cause sudden death,
especially if the second stage is prolonged. At times there is
collapse and death shortly after delivery. The mortality of heart
disease in pregnancy varies in the reports on various series from
4 to 85 per cent. Babcock[132] says that the mortality in mitral
disease in pregnancy is 50 per cent.; that in disease of the aortic
valve is 23 per cent. These figures are far above those given by
later obstetricians of skill. Fellner and Demelin, in ninety-four
and forty-one cases respectively, had a mortality of only 6.3 and
5 per cent. Hirst says he never lost a case. Jaschke[133] found a
mortality of only 4 per cent. in 1548 cases of pregnant cardiopaths.
A great danger is in treating heart conditions by general rules,
and in giving digitalis and other drugs without discrimination.
In uncompensated heart conditions many of the children die from
prematurity, abruptio placentae, diseases of the placenta, or
asphyxiation.
[132] _Diseases of the Heart._ New York, 1905.
[133] _Medizin. Klinik_, February 25, 1912.
Even those obstetricians who induce abortion at any stage of
gestation when they deem the woman's life in danger say that heart
disease in itself is not an indication for abortion unless there
is chronic decompensation with myodegeneration and renal or hepatic
insufficiency. Expectancy is the rule. Lusk advises abortion as soon
as mitral stenosis is discovered.
Surgeons of the Mayo Clinic, in a report[134] on Operative Risk in
Cardiac Disease, hold that a valvular lesion is not a rational basis
for judging a cardiopath so far as prognosis in a surgical operation
is concerned, but this statement is not true for an obstetrical
case. If we except angina pectoris and related diseases, the four
disorders of the heart's mechanism that surgeons deem the worst risks
in operation are auricular fibrillation, auricular flutter, impaired
auriculoventricular conduction, and impaired intraventricular
conduction. These conditions are usually accompanied by extensive
lesions of the heart muscle.
[134] _Jour. Amer. Med. Assoc._, lxix, 24.
In auricular fibrillation there are rapid incoördinate contractions,
twitchings in individual muscle bundles of the auricular wall. The
auricle loses its power to pump the blood and dilates. The pulse is
commonly arhythmic and rapid. A permanent fibrillation is worse than
a paroxysmal state. The condition is found especially in advanced
cases of exophthalmic goitre. In the Mayo Clinic the operative
mortality in seventy cases of exophthalmic goitre with auricular
fibrillation was only 2.8 per cent.
In auricular flutter, or heart block, there are foci of irritation
in the auricular wall which cause rapid coördinate contractions.
The auricle may contract twice as often as the ventricle, and
the pulse may be regular or markedly irregular. The stimulus for
heart contraction normally reaches the ventricle from the auricle
by passing along the bridge of primitive tissue which connects
the auricle and ventricle. This bridge may be so affected that
the stimulus is delayed, or prevented at times from crossing
over, or completely blocked. One patient with complete heart
block was operated upon at the Mayo Clinic three times in eleven
years for appendicitis, cancer of the breast, and the excision of
recurring skin nodules, and is still alive and reasonably well.
In intraventricular block the risk of operation is worth taking,
according to the opinion at the Mayo Clinic, where there is
exophthalmic goitre or tonsillitis.
In general, where there is question of surgical operation on a
cardiopath, no such operation should be done unless there is definite
ground to believe that the operation is essential to improve the
heart condition or restore reasonable health. Extremely severe
cardiac disease can be relieved or even completely cured by the
surgical removal of infectious, mechanical, or toxic sources of heart
degeneration, especially goitre. When the myocardial insufficiency
is so marked that no medical treatment reëstablishes a reasonable
compensation, no surgical operation is permissible. The medical
treatment is the only test to learn whether the heart can be put
into a condition wherein it will withstand the anesthesia and the
operation. Life depends on ventricular action, not on auricular, and
the ventricular reserve is the standard for judgment in these cases.
Fibrillation and heart block are grave conditions when found in
pregnancy, but disease of the mitral valve because of frequency is
more important, and when compensation is unstable mitral lesions
are dangerous. In mitral stenosis the enlarged uterus in the last
months of gestation, by crowding the intestines and diaphragm,
embarrasses the heart. As the diaphragm cannot descend well, the
flow of blood out of the right ventricle is not aided by respiration
as in normal conditions. Pressure on the abdominal veins increases
the blood tension and throws greater work on the left ventricle. In
the expulsive stage of labor there is danger of the right ventricle
giving way under the added strain.
In mitral regurgitation the left ventricle is dilated, and in
pregnancy the regurgitation is increased by the peripheral resistance
or obstruction. If the dilated ventricle is also hypertrophied it
stands the strain much better. In the second stage of labor the
danger is the same as in mitral stenosis. In disease of the aortic
valve the strain of child-bearing is on the left ventricle, but
patients in this condition undergo labor more successfully than do
those with mitral disease.
Labor in any cardiac disease requires close watching even when the
compensation is good. There is always a possibility of collapse in
the third stage or during the puerperium. The obstetrician must
stay by the bedside, and he is to have everything ready for a sudden
emergency, which is likely to result in death if not instantly met.
All the instruments for operative delivery are to be kept sterilized
and ready for immediate use. When symptoms of imminent collapse
appear, delivery is to be done at once. If a cardiopath collapses in
the early stages of gestation, before the child is viable, the rule
explained in the chapter on Abortion holds--the child may not be
killed by removal to save the woman's life.
Jaschke,[135] in his consideration of 1548 pregnant cardiopaths,
found that seven-eighths went to term, and that the women were
prematurely delivered in only about 9 per cent. of the total number
of cases. Therapeutic interruption of pregnancy was necessary in
only about 1 per cent. The high mortality reported by many good
obstetricians is a proof that the treatment of cardiac conditions
requires an experience in clinical medicine and a skill lacking, as a
rule, in specialists who are not internists.
[135] _Loc. cit._
A combined mitral and aortic disease with great enlargement of the
heart, heaving of the chest wall, and some protrusion makes pregnancy
very dangerous. Osler thinks mitral insufficiency in itself not
very dangerous. He had one patient with such a condition, a loud
apex systolic murmur, and some enlargement, who bore nine children
and lived to past sixty years of age. Mitral stenosis is not so
favorable, but even in extreme stenosis some women bear several
children without collapse.