Heart disease and pregnancy

Department CONDUCTED

of Reviews BY HUGO

Pregnancy

EHRENFEST,

Complicated

and Abstracts

M.D.,

ASSOCIATE

EDITOR

by Disease

Heart Disease and Pregnancy. The Lancet, London, :MacKenzie: 1921, cc; 1163. During the early months of pregnancy practically no changes in the circulation can be detected. Towards the sixth month response to effort begins to be noticeable in breathlessness’after slight exertion. At about the seventh month the heart frequently is displaced until the apex is pushed out one inch beyond the left nipple line, and upwards to the fourth interspa,ce. This change was thought due to hypertrophy of the left ventricle, an assumption for which MacKenzie has been unable to find any anatomic evidence. In some patients the veins of the legs, of the thighs and vulva swell. Ilemorrhoids are frequent. These changes are the result of actual pressure on the veins and not of back pressure from the heart. Marked change in the peripheral vascular system, in the smaller arteries and veins, is particularly evident in the breasts. Varicose veins are common in people with perfectly healthy and efficient hearts. Not the result of back pressure is a pulsation in the veins of the neck. Among healthy women these pulsations are present at one time and absent at other times. The writer carefully explains. this phenomenon. Swelling of the legs, not caused by nephritis, is common. During pregnancy irl- many patients the face becomes tinged a,nd dusky while the lips become dark red. Many patients suffering from cardiac disease show abnormal cireulatory signs during pregnancy. The great majority, however, pass through pregnancy, con.finement and puerperium with no trouble. Some cases of mitral stenosis do not suffer in the least, while others suffer severely. Casesof arrythmia show great. variations, the great- majority passing safely through. Cases, again, in which the heart iS weakened from causesbut, presents no abnormal physical signs, such as murmurs or irregularity, bear pregnancy well and seemlittle the worse afterwards. There are two forms of heart force: one, sufficient for the needs of the body when at rest-the rest force; and another held in reserve and used only when an effort is made-the reserve force. The pregnant state imposes more work on the heart not only in connection with the maintenance of placental circulation but also in respect of the additional weight carried by the mother. There are also disturbing factors in the form of interference with the shape and movements of the chest wall, and displacement of the heart itself which call upon the reserve force.

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The first signs of heart failure are a diminution of its power to respond to effort and the subsequent functional impairment of organs inadequately supplied with blood. Diminished circuIation through the cleansing organs of the body leads secondarily to an accumulation of waste products in the blood. Its consequences react upon all the organs expressing themselves chiefly in breathlessness and pain in the heart One or the other of the symptoms is always present, however region. slight the degree of heart failure. Dropsy and enlarged liver are sometimes spoken of as cardinal signs of heart failure, but they occur only in heart failure from certain diseases and in an advanced stage of the condition. Pulmonary stasis tends to occur in eases of pregnancy complicated by mitral stenosis. MacKenzie found that while crepitations at the bases of the lungs were of relatively frequent occurrence in healthy pregnant women as well as those suft’ering from heart disease, they were of serious significa.nce and an indication of danger only when the pregnancy was complicated by heart disease. They are, in his opinion, due to edema occasioned by a diminution of the force of the right ventricle. The danger in mitral stenosis lies in the addition of the embarrassment caused by the pregnancy to the already existing pathology. Back pressure is a factor only in some cases. In mitral stenosis the left auricle undeniably is often embarrassed and in some eases the pulmonary circulation shows this disability. About 90 per cent of the cases of heart failure with dropsy and enlarged liver observed by MacKenzie were cases of auricular fibrillation. Moreover in the great majority of eases of heart strain, i.e., where heart failure with breathlessness had suddenly set in while the individual was making a violent or prolonged effort, the failure was due t,o the sudden onset of auricular fibrillation. It, is often attended by little or no impairment of cardiac ef%ciency. In such cases the heart muscle is good and the rate of the heart not markedly increased, FSome physicians admit that murmurs may exist without significance, yet to them the difference between murmurs of serious importance and those which are innocent is so vague that they consider it wiser to view all murmurs with suspicion. In no field of medicine this attitude toward murmurs proves so disastrous as in pregnancy. The detection of an innocent murmur has often been a reason for forbidding pregnancy or even marriage. ?'hc writer nest explains in detail the characteristics of physiologic and functional murmurs not necessarily produced by dilatation of the heart, Estimation and discusses their differentiation and proper interpretation. of the siguilicance of murmurs, as of aJ1 other signs, should be based not on the murmur itself but ox the functional efficiency of the heart and on the presence or absence of additional symptoms of cardiac mischief (size, rate? rhythm). The detection of a mitral systolic murmur in a woman who is pregnant or may become pregnant should cause t,he physician to consider the following points: (1) The response to effort; (2) the size of the heart; and (3) the rhythm of the heart. If the response to effort is good and the heart is not Increased in size, then the murmur requires no further consideration, as in all likelihood it is physiologic. If there be an increase in size of the heart, but no diminution in the response to effort, and if the circulation is well maintained, pregnancy may be a!lowed, even if there be a history of rheumat,ic fever. If the size of the

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heart is increased and the response to effort is limited, the case requires careful consideration, It must be determined whether the limitations are or are not due to a temporary cause, and whether or not the heart muscle has been damaged. If there is an irregularity of the rhythm of the heart, its nature must be carefully investigated. Should the irregularity prove to be of the youthful or respiratory type, then there will be no danger if pregnancy is incurred. If, again, it is due to extra-systodes, no fear need be ocIn such instances opinion must be based on casioned by their presence. the presence or absence of other signs (size of the heart, response to effort) . The heart affection most frequently causing danger in pregnant women is a mitral stenosis following rheumatic fever. Back pressure develops as the result of the narrowing of the mitral orifice. There is a tendency to congestion of the lungs. More work is thrown on the left auricle, and right ventricle and auricle. When these begin to fail pulmonary circulation becomes embarrassed. In cases of pregnancy the growth of the uterus adds to this embarrassment. The damage due to rheumatic fever, however, frequently extends also to the heart muscle, later indicated by a presystolic murmur. Therefore, even a short presystolic murmur in the presence of a marked inefficiency of the heart means danger in case of pregnancy. When the heart is large or irritable, and effort readily produces palpitation and breathlessness, even if there be no diastolic murmur7 pregnancy should be forbidden. Aortic stenosis apart from regurgitation is extremely rare in the young. In general, pregnancy may be permitted in a young woman with aortic regurgitation, if there is no Corrigan pulse, if the heart is not, or only slightly, enlarged, and if the response to effort is good. The importance of irregularity of the heart’s action has not been sr;fficiently recognized. Even today, few physicians, and evidently no obstetricians, have made themselves familiar with this subject. As a consequence the subject is shrouded in mystery ; and where we get mystery we get fear, and we find people with irregularities treated like peoIn pregnancy we have to deal chiefly with three forms ple with murmurs. of irregularity : respiratory irregularity, extra-systoles, and auricular fibrillation. In the respiratory irregularity, probably the most common of all, the pulse is continuously varying in its rate. When the patient is made to breathe slowly a,nd deeply, the relationship of the altering rhythm with the different, phases of respiration. can easily be determined. Respiratory irregularity is common in healthy young women and occurs in women of mature years, especially if nervous. In no case should it be a reason for treatment or a bar to pregnancy. The extrasystolic irregularity is due t,o a premature contraction of the ventricle, When this irregularity is the only abnormal sign it can be ignored. MacKen.zie found extrasystoles present in 50 per cent of healthy pregnant women. The form of irregularity which is most commonly associated with heari failure in women at the child bearing age is t,hat due to fibrillation of an auricle. The astonishingly good effect of digitalis in these cases has been convincingly shown by MacKenzie. The aut,hor’s experience with pregnancy in women with auricular fibrillation is limited to half a dozen cases. All gave a history of rheu-

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matic fever and all bad mitral stenosis. In each case the advance of pregnancy was accompanied by increasing signs of heart failure. In all but one, premature labor set m between the sixth and seventh months. 811 patients lived through the confinement, but none ever recovered the former degree of health. In his experience pregnancy does not produce immediate heart failure in these cases, but so weakens the organ that it hastens the fatal issue. MacKenzie believes that auricular tibrillation should be a ba.r to pregnaney. Should pregnancy have occurred, careful observation must be maintained. There are other abnormal rhythms which may have to be considered in the pregnant state. The most common of these is known as auricular flutter. This form of parosysmal tachycardia may occur with different types of heart trouble. Its significance in pregnancy should, therefore, be considered in relation to the presence or absence of disease. The neurotic heart is a very distinct type in which the symptoms are due mainly to disturbances of sensation. Attacks of great severity, resembling angina pectoris, sometimes arise. Pregnancy can safely be undertaken by these people. It often does them a great deal of good. When congenital defects of the heart exist and the organ is large, or when there is cyanosis or clubbing of the fingers, the response to effort will be so limited that pregnancy obviously is a definite danger and should be avoided. When on the other hand, the heart is normal in size, or only slightly enlarged, the response to effort good, and no cyanosis present, then, notwithstanding any physical sign, such as a murmur, marriage and pregnancy may be allowed. With an inefficient heart, the pregnant patient should be examined weekly for signs of heart failure. The patient should be confined to bed sitting up or lying propped up, since lying down tends to hamper the circulation in the bases of the lungs. Several times a day she should be made to breathe deeply to assist the right heart in expediting the If the heart failure thus is kept in flow of blood through the lungs. check, the pregnancy can be allowed to go to fu11 time. When labor has a,dvanced so far as to justify interference, it should be terminated artificially, thus avoiding the strain of the last stage. When the heart failure is so extreme as to threaten life, intervention is necessary and labor should be induced. Sleep is essential during pregnancy. If necessary, the milder hypnotics should be given. This monograph represents the most exhaustive and instructive study of this important, problem offered in recent years. Only its salient points, of interest to the obstetrician, are given in this abstract. NOR,MBN

F.

MILLER.

Bowktte : .A Note on the Heart -h regnancy and Labor, Dublin nal of Medical Science, June, 1921, No. 16, p. 260.

Jour-

The effect of pregnancy on the physiology of the heart is considered by the author to be evidenced first, by the dlsplacemeut of the heart upward and outward, and second, by a certain amount of hypertrophy. The first effect is readily demonstrable, but the degree of hypertrophy is subject to question. Corroborating MacKenzie, Rowlette finds evidence of disturbed function “incidental to pregnancy” : “ (a) Limitation of the field of cardiac