Congestive Phenomena Occurring in Pregnant Womenwith Heart Disease

By C. SIDNEY BURWELL, M.D., AND JAMES METCALFE, M.D.

P REGNANT women with heart diseasemay exhibit the signs of either pulmo-

nary or peripheral congestion. Evidences ofvenous congestion in the lower extremities,including the development of pitting edema.are not unusual during pregnancy in normalwomen and should not be taken as evidenceof danger, even in the cardiac patient, with-out supporting data. In pregnant women withheart disease significant congestive phenome-na occur most often in association with mitralstenosis. In this situation they are due to theobstruction at the mitral valve that leads tocongestion and edema of the lungs. In asmaller number of pregnant women with heartdisease congestive phenomena are due to nyo-cardial failure, and in this case the congestionmay affect either the pulmonary or the periph-eral circulation according to whether leftor right ventricular failure is present. Since,in well over half our pregnant cardiac pa-tients, the major hemodynamic problem ismitral stenosis, significant congestive phe-nomena during pregnancy are observed mostfrequently in the lungs.The left ventricular failure that rarely oc-

curs in pregnant women with heart disease ismost often associated with aortic valve dis-ease and only rarely with hypertension. Ven-tricular failure may also occur in associationwith specific disease of the cardiac musele.The most common cause is acute rheumaticnyoearditis. It has also been observed in other

From the Department of Medicine, Harvard Med-ical School, and Dr. Burwell 's Laboratory, BostonLying-in Hospital, Boston, Massachusetts.

Supported in part by grants from the NationalInstitutes of Health, U.S. Public Health Service, andfrom the Josiah Macy, Jr. Foundation.

This work was carried out during Dr. Metealfe stenure as an Established Investigator of the AmericanHeart Association.

varieties of myocardial disease including myo-cardial infarction.Whatever the predominant cardiac lesion in

congestive failure may be, such failure isintensified or indeed precipitated by a longlist of extracardiae factors, including certainspecific physiologic changes of pregnancy.

Physiology of the Maternal Circulation DuringPregnancy

The changes in the maternal cardiovascularsystem during pregnancy are complex and in-completely understood, but 3 of them, theincreases in heart rate, cardiac output, andblood volume lead directly to vascular con-gestion. These 3 changes are closely re-lated, at least in time; all reach their high-est level, not at term, but from 6 to 10 weeksbefore delivery, and then deeline significantlyuntil labor ensues. At their peak values, theresting pulse rate averages 10 beats per min-ute above the nonpregnant value, the restingcardiac output is increased by about 40 percent, and the blood volume is elevated byabout 30 per cent of control values. It shouldbe remembered, however, that this statementof general performance indicates only theaverage behavior of a large number of preg-nant women with and without heart disease;in the individual patient variations in theintensity and in the time of maximal changeundoubtedly occur. The mechanism by whichthese changes may lead to disability and oc-casionally to death in pregnant women withheart disease is best understood if mitral ste-nosis is taken as an example.

Physiology of Mitral StenosisThe basic defect hemodyiiamically in mi-

tral stenosis is an obstruction to the flow ofblood from left atrium to left ventricle. Themaintenaniee of a normal volume of blood flow

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through the narrow valve orifice requires anincrease of pressure in the left atrium, and apressute rise of similar magnitude in the pul-monary veins and pulmonary capillaries. Anincrease in cardiac output in such circum-stances necessitates a further rise in leftatrial, pulmonary venous, and pulmonarycapillary pressures. Effective blood flowthrough the mitral valve occurs only duringdiastole; the increase in heart rate that ac-companies pregnancy cuts down the diastolictime for flow through the mitral valve, so thata further increase in left atrial, pulmonaryvenous, and pulmonary capillary pressure isnecessary to maintain cardiac output. Theincrease in total blood volume that accom-panies pregnancy is apparently shared be-tween the pulmonary and peripheral vascularcircuits. This increase in pulmonary bloodvolume distends the pulmonary vascular sys-tem and, in patients with significant mitralstenosis, leads to still greater increases inpressure in the capillaries. When the pressurein these vessels exceeds approximately 30 mm.of mercury, it leads to transudation of fluid;if pulmonary capillary hypertension persists,the transudation causes pulmonary edema.The woman with mitral stenosis, then, is inincreased danger of developing pulmonaryedema during pregnancy. Such pulmonaryedema is due to mechanical obstruction toblood flow and is different in mechanism fromthe pulmonary congestion secondary to leftventricular myocardial failure. The distinc-tion between these 2 varieties of pulmonarycongestion should be kept in mind in planningthe therapeutic approach in a given patient.

Prevention of Venous CongestionThe principle of managing mitral stenosis

during pregnancy is to adopt ways and meansthat limit or restrict the cardiac output, thetotal blood volume, and the cardiac rate. Thetotal cardiac burden of the pregnant womanincludes not only pregnancy but a great vari-ety of other burdens. The physician must beconcerned with the algebraic sum of thosefactors that influence the output of the heart,the rate of the heart, or the volume of blood

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in the vascular tree. He must think constantlyof the total cardiac load resulting from thepatient's total situation, inieluding pregnancy.

In most pregnant women with heart disease,congestive phenomena can be prevented by aprogram of management that applies theseprinciples to the individual patient. The ob-jective of management is not necessarily tokeep the total cardiac load at a minimum.What is needed is to keep the total load safelywithin the tolerance of the individual patient.

In constructing such a program of manage-ment we must consider factors that have 3essential characteristics. First, they are notnecessary to the continuation or success of thepregnancy; second, they impose a cardiac bur-den; third, they can be limited or eliminated.Important individual factors in patients' livesthat lead to an increase in heart rate, in car-diac output, or in blood volume include thefollowing: (1) physical activity, (2) emo-tional stress, (3) ectopic rhythms with taehy-cardia, (4) anemia, (5) obesity, (6) infec-tions, (7) hyperthyroidism, (8) factors thatinfluence the blood volume, such as infusions,transfusions, and increased intake of sodium.Some of these factors are more frequentlyoperative during pregnancy than in the non-pregnant woman. For instance, iron deficiencymay manifest itself for the first time as ane-mia during pregnancy. Infections of the up-per respiratory tract or the genitourinarytract are common in pregnant women. Thehypertensive toxemias of pregnancy some-times add to the total burden in women withheart disease; control of the hypertensive dis-orders of pregnancy by sodium restrictionhas been an important factor in lowering thematernal mortality in women with heart dis-ease. So has the virtual elimination of puer-peral sepsis.

Attention must also be given to preventionof 2 specific diseases, acute rheumatic feverand subacute bacterial endocarditis. In our

opinion prophylaxis against rheumatic feveris advisable in all patients with rheumaticheart disease during and for an indefiniteperiod after pregnancy. The eustomary pro-

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phylaxis against bacterial endocarditis is alsoemployed during anid for 3 days after labor.

Management of Venous Congestion-In a rare patient from the preniatal mnedi-

cal clinic and an occasional patienit first seenlate in pregnancy, symptoms aind signs of ve-nous congestion have developed. Peripheraledema, while disturbing in its prognostic im-plications, is seldom dangerous. Pulmonary-congestion aiid pulmonary edeima carry dan-ger of immediate death and therefore demandlprompt and organized treatment."Hospitalization and Rest

"Every patient with pulmolnary congestionobserved in the clinic is admitted to the hos-pital with the objective of immediate rest. Webelieve this is achieved by allowing the pa-tient to pick her own best resting positionuntil pulmonary edema has cleared. This isoften in an easy chair. A bed is made morecomfortable by placing its 'head' legs on four-to eight-inch blocks so that the entire frameis tilted. Elevation of the head of the bed andflexion of the patient 's knees allow comfort-able maintenance of the sitting position. Elas-tic stockings are applied to above the kneeto combat thrombo-embolic disease. The useof a bedpan is usually more tiring than the useof a bedside commode or travel to the toilet bywheelchair."Sedation

'inereased mental and physical rest is theaim of sedative therapy. In our experiencemorphine in small, repeated doses has no equalfor this purpose. An initial dose of 10 mgm.is given intramuseularly, followed at four-hour intervals by equal or smaller doses, asindicated. "

Sodium Restriction and Diuresis

"The inereased blood volume of pregnancyis one of the identifiable factors in distentionof the pulmonary vascular tree. If pulmonarycongestion appears, sodium restriction to

*Some of the following paragraplhs are extractedin toto from the book, Heart Disease and Pregnancy,Physiology and Management, by the authors.' Theseextractions are indicated bv quotation marks.

about 200 mgm. daily is usually effeetive evenif a similar program at home has not pre-vented the development of pulmonary conges-tioln. In such a diet, salt-free milk and breadare used. Dialyzed low-sodium mnilk is nowavailable. It is palatable and relatively inex-pensive. "

In patients who accept anid follow rigidsodium restriction, diuretic agents are seldomnnecessary in our experience. In patients ex-hibiting important venous congestion despitesodium restriction, diuretic agents are eni-ployed. Before enterinig upoln a program offorceful or prolonged diuretic attempts, thephysician must evaluate the importance ofveenous congestioni in bis patient. Edemna ofthe legs, unaccompanied bv other evideiiee ofvenous hypertension, is less dangerous antidisabling than strenuous diuretic medication.When a program of diuresis is decided upon,our current practice is to begin with 500 mng.of chlorothiazide twice daily for 3 days ofeach week, judging our success by changes infasting body weight measured daily. andevaluating the serumii electrolytes each weekbefore diuretic therapy is reinstituted. Whensuch a program does not result in satisfactoryimprovement and weight loss, intramuscularmercurial diuretics are tried. The possibilityof electrolyte depletion by these measuresshould be kept constantly in mind.Methods of Decreasing Venous Return to the Heart

"The venous returmi can also be diminished,at least transiently. by the application oftourniquets to the extremities or by phle-botomny. These measures are frequently help-ful in the acute emergency of pulmonaryedema. The level of blood hemoglobin shouldbe checked before phlebotomy, but we haveresorted to this measure in emergency situ-ations in anemic patients knowing, in somecases, that tran-sfusion would subsequently benecessary."When tourniquets are used to obstruct

venous return they may initially be placed onall four extremities if they are not so tightlyCapplied that arterial obstruction results. Athalf-hour intervals one is removed and re-

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placed after one half-hour, at which time an-

other is removed, rotating the obstruction inan orderly serial fashion. Sudden removal ofseveral tourniquets would result in a suddenlarge increase in venous return which mightbe dangerous. "

Methods of Slowing the Heart Rate

" In patients with mitral stenosis, tachy-cardia is dangerous since it decreases the timeavailable for diastolic flow through the mitralvalve. When atrial fibrillation or paroxysmalatrial tachycardia is present, digitalis is thedrug of choice in controlling heart rate. Inthe presence of normal sinus rhythm this drugis frequently disappointing in producing a

decrease in heart rate. Indeed, no adequatemethod of decreasing the heart rate in sinustachycardia exists. Serpasil is currently beingtried for this purpose in our patients. If thetachyeardia is accentuated by anemia, thyro-toxicosis, or blood-loss, measures designed tocombat these are indicated."

Digitalis

"Pulmonary congestion is not always due tomyocardial failure. Indeed, myoeardial fail-ure is an unusual cause of pulmonary conges-

tion in our patients; the common cause is an

obstruction to blood flow through a stenoticinitral valve with pulmonary vascular hyper-tension secondary to the mechanical impedi-ment. In such a situation the chief therapeu-tic result of digitalis is to slow the heart rate.

"When pulmonary congestion or edema de-velops in patients with aortic valve disease,then digitalis is indicated. We have, in gen-

eral, sought to anticipate ventricular failurein such patients, using oral doses of digitalisfolia (0.1 Gm. three times daily for five days,then 0.1 Gm. daily) at the earliest suspicioiiof myocardial failure."In the presence of pulmonary edema,

rapid digitalization is employed, even in pa-

tients we judge to have predominant mitralstenosis. We have used digoxin for this pur-

pose, beginning with 0.5 mgm. intramuseu-larly, repeating this dose at four-hour inter-vals for a total initial dose of 1.5 mgm. over a

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12-hour period. We do not use this glycosidefor maintenance therapy but shift to digi-talis leaf.'

Oxygen

" The use of oxygen in the treatment ofpulmonary edema has many advocates. Itcertainly appears to be indicated if it causessymptomatic relief, and is probably indicatedwhen it can be tolerated without apprehen-sion. Unfortunately it frequently does causeapprehension and restlessness, and in suchsituations its continuance must be decidedupon in the light of the iiidividual case. Ingeneral, an oxygen 'teiit' is tolerated morereadily thani oxygen administered through anasal tube, while the face mask is badly re-ceived by most patients."

Other Measures

"The administration of amninophylline inthe management of pulmonary edema is indi-cated for several reasons. It is a broneho-dilator, and maanv believe that bronehocon-striction frequently occurs in conjunetioniwith pulmonary edema. It has the additionaladvantage of its properties as a xanthine di-uretic, and Goodman and Gilman2 ascribedirect myocardial stimulation to the xanth-ines. Usually 0.25 Gm. is given slowly intra-venously."

Prevention of Recurrences

"Following recovery from an acute episodeof pulmonary edema, the patient 's activity,sodium intake, sleeping position and total pro-gram of living mnust be rescheduled, to avoidrecurrenees. In pregnant patients strict modi-fication may be necessary only for the dura-tion of pregnancy, but plans for future medi-cal care, including consideration of mitralvalvotomy, should be carefully laid for pa-tients who have experienced pulmonary edema."The importance of sodium restriction has

already been emphasized. Our experience in-dicates that the diet actually consumed oftendiffers from that recommended. Thereforepatients on restricted sodium intake shouldbe seen weekly."In our clinic all patienits are encouraged

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to report at once if symptoms develop or in-crease. When a cardiac patient misses an ap-pointment we have learned to be concerned.Such patients may fail to turn up becausethey are in need of additional medical help."

Cardiac Surgery During PregnancyDespite rigid limitation of the total burden

on the patient's heart, an occasional womanis unable to tolerate the cardiac expendituresof pregnancy. If this is judged to be the casein a given patient and if surgical measuresare applicable, these should be employed be-fore pregnancy is undertaken. Emergencycardiac surgery during pregnancy has notbeen found necessary in our experience todate, but we may sometime see a patient, earlyin pregnancy, in whoin evidence of pulmonarycongestion persists, despite rigid restrictionsaccurately followed. In such a patient wewould prefer interruption of pregnancyrather than cardiac surgery as the first steptoward cardiac rehabilitation. This is some-times unacceptable for social or religious rea-sons, and therefore cardiac surgery may-rarely be indicated even during pregnancy. Itis imperative to make the necessary judg-ments before persistent congestive failureforces the hand of the surgeon.The cardiac burdens of pregnancy exhibit

certain known variations. The cardiac output,the total blood volume, and the heart rate allreach a maximum 6 to 10 weeks before term.Many patients experience an improvementin symptoms as the point of maximum loadis passed and they come into the period ofless severe load which precedes delivery.Hamilton and Thomson3 showed that the in-cidence of congestive phenomena in pregnantwomen with heart disease was highest fromthe thirtieth to the thirty-fourth week, whichcorresponds to the time of the maximumhemodynamic load of pregnancy.

Labor and Postpartum PeriodMost patients who have gone through preg-

nancy without exhibiting congestive phe-nomena or whose congestive symptoms havebeen controlled by appropriate therapy are

able to go through labor and delivery with-out intensification of congestive failure. Itmay be pointed out that the work of labor isdiscontinuous and that periods of increasedwork and increased oxygen need are sepa-rated by periods of relative rest. It should beemphasized again that the work of the heartin terms of cardiac output is significantlysmaller at term than it was 6 to 10 weeks pre-viously, and therefore at the time of deliverya pregnant woman with heart disease has aniamount of cardiac reserve which she did nothave a month before. It has been found byexperience to be important that women withheart disease come up to the time of deliveryand labor in optimum condition. Skillfullyorganized and executed delivery is a vitalmatter and here, while continued close cooper-ation is essential, the obstetrician plays thedecisive role. The presence of heart disease isnot an indication for cesarean section but ifa good obstetrical indication for abdominaldelivery exists, there is no experience thatwould warrant the denial of such a procedureto a woman with heart disease.

Congestive phenomena are occasionally in-tensified or may even develop for the firsttime during the postpartum period. Duringthis period an intricate series of profound re-adjustments is being made in the maternalphysiology. Some of these adjustments arethe reestablishment of normal water andelectrolyte balance, a new equilibrium amongthe hormones and the tissues that producethem, and appropriate ehanges in the bloodvolume and in the total capacity of thevascular system. Too little is known aboutthe physiology of the postpartum period tomake a didactic or arbitrary application tothe management of heart disease. It must beremembered that heart failure can get worseor develop during this period and that theheart disease which has required managementduring pregnancy still requires managementafter delivery. Moreover, the patient herselfis in a more complex situation and has addi-tional family responsibilities. These mattersshould all be taken into account in planning

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the postpartum program of a cardiac patient.If congestive phenomena occur during thisperiod, they should be managed by the ac-cepted methods.

In larger scope, pregnancy is an episode inthe life of the patient with heart disease-animportant episode accompanied by increaseddanger, but self-limited in duration and gen-erally successfully tolerated. As our under-standing of the physiology of pregnancy andthe physiology of heart disease has increasedthe safety of pregnancy in the cardiac pa-tient, other aspects of pregnancy have be-come increasingly important. One aspectwhich should concern us here is the impor-tance of pregnancy in bringing women undermedical supervision. About 50 per cent ofour patients with heart disease were unawareof its existence before pregnancy. Even underour high standards of living and patient care,a surprising number of women have their firstcolntact (since their own birth) with a phy-sician when they consult him for obstetricalhelp. This has 2 important implications. First,the obstetrician must have a high level ofsuspicion with regard to heart disease and

should develop an effective working relation-ship with an internist for final diagnosis andhelp in effective management. Second, theobstetrician and his medical consultant shouldaccept as part of their responsibility the ori-entation of the patient, not only through thehazards of pregnancy, but through the yearsthat follow. In this sense, pregnancy repre-sents an opportunity for the physician to de-velop a long-term plan for these young womenthat will postpone, and sometimes prevent,the development of congestive phenomena inthe years ahead.

Keep thy heart with all diligence;for out of it are the issues of life.4

References1. BURWELL, C. S., AND METCALFE, J.: Heart Dis-

ease and Pregnancy. Physiology and Manage-ment. Boston, Little, Brown and Company,1958, p. 94.

2. GOODMAN, L. S., AND GILMAN, A.: The Pharma-cological Basis of Therapeutics. Ed. 2. NewYork, The Macmillan Co., 1955.

3. HAMILTON, B. E., AND THOMSON, K. J.: TheHeart in Pregnancy and the Childbearing Age.Boston, Little, Brown and Company, 1941.

4. Proverbs, 4: 23.

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C. SIDNEY BURWELL and JAMES METCALFECongestive Phenomena Occurring in Pregnant Women with Heart Disease

Print ISSN: 0009-7322. Online ISSN: 1524-4539 Copyright © 1960 American Heart Association, Inc. All rights reserved.

is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231Circulation doi: 10.1161/01.CIR.21.3.430

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