CONGESTIVE HEART FAILURE

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REVIEW

ARTICLE

CONGESTIVE

HEART

FAILURE

By John D. Keith, M.D.

Hospital for Sick Children and Department of Pediatrics, University of Toronto

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Aided by a grant from the Ontario Heart Foundation.

ADDRESS: 555 University Avenue, Toronto 2, Ontario, Canada.

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H

EART failure is associated with an in-ability of the heart to empty itself

adequately, with the result that there is a high venous filling pressure and a decrease

in the effective work done by the heart muscle.1 There are several factors that, if

sufficiently severe, will produce congestive heart failure in either infancy or childhood.

These include valvular obstruction or in-sufficiency; mechanical obstruction of the heart as a whole, as in penicardial disease;

the physical effects of large intracardiac shunts which increase the load on one or

both ventricles; the presence of raised pres-sure in the pulmonary or systemic circula-tion; inflammatory reactions in the heart muscle or oxygen lack; and, finally, certain metabolic disturbances, such as

hyperthy-roidism or hypothyroidism.

One or more of these factors may be

operating in the same child, as in rheumatic

fever where myocarditis is associated with

valvular insufficiency, or in congenital heart disease with pulmonary stenosis and pat-ent foramen ovale, where the right

ventri-cle has a high pressure to maintain and is

at the same time being offered cyanotic blood from the coronaries.

PATIENT MATERIAL

In analyzing 1,580 cases of congenital heart disease at the Hospital for Sick Children,

To-ronto, 20 per cent were found to have had

failure at some time. In 90 per cent of these

failure occurred in the first year of life. A list of the various causes of heart failure in the pediatric age group in order of frequency fol-lows.

Transposition of the great vessels 71

Coarctation of the aorta 44

Ventricular septal defect 27

Aortic atresia 26

Endocardial fibroelastosis 22

Atnioventricularis communis

Anomalous pulmonary venous drainage

Single ventricle

Patent ductus arteniosus Isolated myocarditis

Persistent truncus arteriosus Aberrant left coronary artery Coronary calcinosis

Pulmonary stenosis

Tricuspid atresia Aortic stenosis

Tetralogy of Fallot Ebstein’s disease

Pulmonary atresia with intact septum

Total number of cases 304

In certain types of heart defects failure de-vebops in characteristic age groups. For

ex-ample, during the first week of life the most common cause of heart failure is aortic atresia. From 1 week to 1 month, coarctation of the aorta leads. From 1 to 2 months, transposition of the great vessels predominates. From 2 to 3 months, endocardial fibroebastosis is the chief

cause of heart failure, with transportation of

the great vessels second to it.

The actual incidence of type of heart defect in relation to age at onset of heart failure is as follows. Birth to 1 week (20 per cent of total group) : aortic atresia, 44 per cent; transposition

of the great vessels, 10 per cent; coanctation of aorta, 10 per cent; patent ductus arteniosus, 10

per cent; pubmonary stenosis or atresia with

normal aortic root, 8 per cent; Ebstein’s

dis-ease, 8 per cent; other, 1 per cent.

One week to 1 month (18 per cent of total group): coarctation of aorta, 36 per cent; trans-position of the great vessels, 20 per cent; endo-cardial fibroelastosis, 16 per cent; other, includ-ing patent ductus arteriosus, ventricular septal defect, atnioventnicularis communis, paroxysmal tachycandia, pulmonary veins into left superior vena cava, tricuspid atresia and single ventricle, 28 per cent.

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coarctation of aorta, 12 per cent; atrioventricu-lanis communis, 12 per cent; paroxysmal tachy-cardia, 12 per cent; other, 23 per cent.

Two to three months (10 per cent of total group) : endocandiab fibroebastosis, 40 per cent; transposition of the great vessels, 15 pen cent; total anomalous pulmonary venous drainage into left superior vena cava, 15 per cent;

yen-tricular septal defect, 15 per cent; other,

in-eluding coarctation of aorta and truncus arteni-osus, 15 per cent.

Three to six months (14 per cent of total group) : endocardial fibroelastosis, 25 per cent; transposition of the great vessels, 20 per cent;

ventricular septal defect, 15 per cent; total

anomalous pulmonary venous drainage into left superior vena cava, 10 per cent; coarctation of aorta, 10 per cent; atnioventriculanis communis, 10 per cent; other, including aberrant left coronary arising from the pulmonary artery and tetrabogy of Fallot with left to right shunt, 10 per cent.

Six to twelve months (10 per cent of total group) : endocardial fibroebastosis, 57 pen cent; ventricular septal defect, 14 per cent; other, including atrioventniculanis communis, anomaly of the pulmonary veins, patent ductus arteniosus and hypertension, 29 per cent.

One to ten years (10 per cent of total group):

a total of 14 cases, including rheumatic heart disease, paroxysmal tachycardia, isolated myo-carditis, anemia, endocardial fibroelastosis, co-anctation of aorta, aunicubar septal defect and ventricular septal defect.

From a review of the electrocardiograms of these groups, it was found that 40 per cent have right ventricular hypertrophy; 30 per cent, right and left ventricular hypentrophy; and 30 per cent, evidence of left ventricular hypertnophy. Between the two main groups of right and left hypentrophy there is a good deal of overlapping. Thus, there may be an abnor-mally high arterial pressure in both the systemic and pulmonary circuits as well as the presence of an abnormal shunt, resulting in an overload of both ventricles and in the development of biventnicular hypentrophy in the electrocardio-gram; an example of this is coarctation of the aorta with a large patent ductus arteriosus. When biventriculan hypentrophy is present, usually the night ventricular hypertrophy is

dominant.

DYNAMICS OF HEART FAILURE

Early in the last century, the backward pressure theory was supported by Hope2

and his view was generally accepted until

Mackenzie,3 early in the Twentieth Cen-tury, proposed the forward failure theory as the explanation of congestive heart fail-ure. These two points of view have been

brought together in recent years with much

new information gathered by the use of

the intracardiac catheter. It is now

gen-enally considered that, while the backward

pressure is chiefly responsible for the

cmi-cal signs in congestive heart failure,

for-wand failure makes its contribution under certain circumstances.4

There is a series of steps encountered in cardiac response leading eventually to

fail-ure. The first response to increased load on

the heart is hypentrophy of the ventricle

concerned, as frequently develops in

co-arctation of the aorta without cardiac en-largement. This hypentrophy usually occurs before there is any increase in the venous

pressure, but eventually such filling

pres-sure rise appears. This may be controlled,

or kept within physiologic bounds, by

in-creased strength of contraction of the heart

muscle, and also by an increased heart rate.

In time, however, these mechanisms of

rate and strength cease to be adequate. When that point is reached the one

remain-ing means of compensation is an increased

venous filling pressure.

The first rise in venous pressure, then,

may be physiologic rather than pathologic

and does not immediately lead to signs of

failure, especially if the heart muscle can iespond sufficiently to the increased load.

When the burden is excessive and the heart

muscle becomes fatigued or weakened, the clinical signs of failure begin to appear. This state of cardiac muscle fatigue is

re-ferned to by McMichael’ as “hypodynamic.”

He also records that hypodynamic hearts

are the ones most likely to respond to

digi-tabis therapy.

CLINICAL FEATURES OF CONGESTIVE HEART FAILURE

Dyspi,nr. Dyspnea with effort is a nor-mal phenomenon and it may be difficult

to assess whether it is present in

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hearts may have dyspnea on effort without

other signs of congestive heart failure.

Dyspnea at rest, on the other hand, is

frequently present with heart failure in infancy. In a baby a respiratory rate of 50 to 100 a minute is common with congestive

heart failure, and it may go as high as 120

to 149 per minute on occasions. Paroxysms of tachypnea which start rather suddenly

and stop rather suddenly are rare in

child-hood failure; they are much more common

in the cyanotic babies without failure.

It should be remembered that fever,

pub-monary infection, and pyelitis may produce rapid respiratory rates in infancy that

simu-late those seen in infants with heart failure.

VENOUS Pmssunn. In babies in the first

year or two of life, it may be possible to see the external jugular vein sufficiently

cleanly and under conditions such that one may assess the problem of venous pressure. Struggling, crying, or respiratory distress

on the part of the baby will increase the

venous pressure. Furthermore, the amount

of the vein visible may be so short that the

pulsating top of the column may not be

seen.

In small children, when the back of the hand is not too chubby, the venous

pres-sure may be assessed by prominence of the veins in that area and by raising and

bower-ing the hand above the position of the right

auricle one may notice in the sternal notch the point at which emptying of the veins

occurs. These veins should empty if the

hand is held at, or just above, the sternal

notch, with the child at an approximate

angle of 45 degrees.

In the older children, the external

jugu-bar vein may be seen and the top of its distended pulsating column be recognized

more readily. Furthermore, in the older children the position of emptying of the

veins of the back of the hand can be as-sessed more accurately.

It is thus obvious that a clinical

esti-mate of the venous pressure in babies may

be especially difficult. For this reason, in the first year of life the liver size is usually of more value in assessing heart failure.

Livim Sizi. The liver is readily palpable

in infancy and childhood; the edge can be

accurately felt and measured from the

costal margin. This is done preferably on a line from the right nipple to the

umbili-cus. If the liver is 3 fingerbreadths or more from the costal margin it is usually

patho-logically enlarged. It is useful to draw out the margin of the liver with a skin pencil so that one can note change in liver size from day to day. In babies there is often

a marked decrease in size after 24 hours of digitalis therapy.

In infancy and early childhood liver

en-largement is not commonly accompanied

by pain or tenderness of that organ.

PULMONARY Rus. In left ventricular

failure fine pulmonary rales may be heard in the bases. This is a common finding in

adults but is not so frequently noticed in

infants and young children until a rather

severe stage is reached, and a considerable degree of dyspnea is usually present

be-fore the rabes appear. A complicating

fac-ton in congenital heart disease is the ap-pearance of respiratory infections, particu-larly in the presence of pulmonary

hyper-tension. These may precipitate congestive heart failure, and it may at times be

diffi-cult to tell whether the rales are due to infection, to the failure, or to both.

Vrri CAPACITY. Wilson5 has drawn

at-tention over the years to the reduced vital capacity in rheumatic heart disease even

before failure appears. With the onset of failure there is a greater reduction than

before due to the increased congestion in the lung fields. There have been no meas-urements in infants, but there is no doubt

that the effective lung volume is considera-bly reduced by the congestion and edema and that the vital capacity is considerably reduced at any age.

ROENTCENOGRAPHIC SIGNS. Pulmonary

con-gestion may be evident in a roentgenogram of the chest. There is a widespread increase

in the density of the lung fields which indi-cate simple congestion. In the presence of

acute pulmonary edema a diffuse mottling appears which is evident even in the

pe-riphery of the lung fields.

(4)

circula-tion time in an infant or young child is be-tween 6 and 12 seconds but when

conges-tive heart failure is present the circulation time may be prolonged to 30 to 40 or 50 seconds. This delay is due in part to the

engorgement of the systemic veins and in part to the vascular bed of the lungs.

GALLOP RHYTHM. The presence of gallop rhythm in congenital heart disease, isolated

myocarditis, and nephritic heart disease usually denotes congestive heart failure. This is not true for rheumatic heart disease

where the presence of gallop rhythm is of more benign import, although still

signifi-cant.

There are a number of extra heart sounds heard in infancy and childhood that may simulate the gallop rhythm. These include the physiologic third sound, the aunicular

or presystolic sound (especially in the presence of a lengthened conduction time),

a systolic click or systolic sound and finally, the opening snap of the mitral valve in mitral stenosis.

The most commonly heard gallop in the pediatric age group is the protodiastolic sound coming 0.10 second after the second

sound. It is generally thought to be due

to the sudden distension of the ventricles in the rapid filling stage of diastole. This

same mechanism produces the normal third

heart sound; therefore, there may be diffi-culty in distinguishing between a physio-logic and pathologic gallop. In normal in-fants and in older children the physiologic

third sound is usually not heard, or is so faint as to be recognized as insignificant. Thus the presence of a well heard third sound is usually considered to be

patho-logic, and in most forms of heart disease

in infancy heralds the onset of congestive heart failure.

Cyosis. Cyanosis in infancy and child-hood is usually due to 1 of 3 origins. The first is the type seen in congenital heart

disease resulting from a shunt of cyanotic blood into the systemic circulation. In the presence of failure, this shunt may be aug-mented bringing to the surface signs of

unsaturation in the milder cases, and a

deepening of the cyanosis in the severe defects. Transposition of the great vessels, aortic atresia and single ventricle are good

examples of this.

The second type of cyanosis, which is referred to as central cyanosis, is that due to pulmonary congestion or disease with

inadequate oxygenation in the lungs. We

have studied this in babies whose failure

is not accompanied by a shunt and

approxi-mately half of these cases show a decrease

in their arterial oxygen saturation,

depend-ing largely on the degree of failure present.

If the failure leads to death, presumably all in this category would ultimately show

cyanosis of this type in the terminal stages.

Coarctation of the aorta, isolated

myocardi-tis, endocardial fibroelastosis may exhibit

cyanosis of this category.

The third type is due to a vasomotor ef-feet in the small vessels and capillaries leading to a slowing of the blood stream

and desaturation of the hemoglobin. This

type of cyanosis may appear in heart failure and is usually associated with cold cx-tremities. When oximetry is carried out

the oxygen saturation of the arterial blood

is found to be normal indicating its

pe-riphenal origin. Examples of this group are seen in pulmonary stenosis without a shunt,

but also can be recognized at times in

endo-cardial fibroelastosis, isolated myocarditis and coarctation of the aorta.

It is obvious in reviewing these three

common causes of cyanosis that one or more may be operating in any one child, that is,

a baby with a large ventricular septal de-feet and pulmonary congestion may be

cyanotic because of inadequate

oxygena-tion of the blood in the lung fields as well

as from a partial shunt from the night to left

ventricle and aorta.

SEDIMENTATION RATE. It has been

necog-nized for many years that an elevated sedi-mentation rate in patients with rheumatic

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rheu-matic heart disease. In the acute illness of rheumatic fever with an overwhelming

in-fection and heart failure, the sedimentation rate remains high. In the chronic failures with edema, if the edema clears, the sedi-mentation rate returns to its previously

dc-vated level until the infection subsides.

BLOOD PREssuiiE. In the past, blood

pres-sure in patients with heart failure has been reported to be low or normal in the majority

of cases but occasionally elevated. We have studied this problem with some care in infants with coarctation of the aorta and heart failure. In most instances where low

systolic pressure is evident on admission to

the hospital, after successful treatment with digitalis along with the relief of the failure the blood pressure rises to the usual

cx-pected level. We have determined the blood pressure levels in babies in failure from a variety of causes. In those that are only

slightly decompensated the pressure is

usually in the normal range. When the failure has been severe and the baby’s con-dition poor, a low reading is common, some-where between 60 and 80 mm. of mercury

for the systolic pressure; the normal read-ing for babies is between 80 and 100 mm.

of mercury.

HEART RATE. The heart rate is usually

in-creased to levels over 100 to 150 in children over a year or two in age with congestive

heart failure. In infants there is commonly a tachycardia of 150 to 200 beats per minute

in the presence of failure. There are many causes for this response, but congestive heart failure is associated with a rise of pressure in the right auricle and great veins which sets in motion the Bainbridge reflex

by which vagal effect is diminished and the

heart rate increased. This is a useful

me-chanism, since it produces greater cardiac output as the venous pressure and heart rates rise together.

RIGHT HEART FAILURE

This is the most common form of heart failure found in childhood. It is found in aortic atresia, transposition of the great vessels, anomalous pulmonary venous

drain-age, aunicular septal defect and, to some degree, in ventricular septal defect,

atnio-ventriculanis communis, preductal coarcta-tion and others.

The signs indicative of right heart failure

are increased venous pressure, dyspnea, enlarged liver and edema. All cases will

show venous distension and increased pres-sure, and the majority in the pediatric group

with right heart failure will also show en-bargement of the liver. Edema is less fre-quently noted but appears in approximately

50 per cent of the cases.

LEFT HEART

FAILURE

,

The chief causes of left heart failure in the pediatric age group are coarctation of the aorta, endocardial fibroelastosis,

parox-ysmal tachycardia, isolated myocarditis,

patent ductus arteniosus and, to some de-gree, ventricular septal defect and

atrio-ventricularis communis.

In coarctation of the aorta there is an

elevation of the blood pressure to a degree that places a large burden on the heart

muscle and in infants this is frequently aug-mented by an open ductus arteriosus, either above or below the coarctation, leading to heart failure, with the left failure

pre-dominating over the right.

In endocardial fibroelastosis the

thick-ened endocardium acts bike a ball in the left ventricle interfering with the normal

contraction, thus leading to left ventricular hypertrophy and ultimately to failure.

In paroxysmal tachycardia the heart is

beating so rapidly that it cannot empty it-self adequately with the result that the venous pressure rises and eventually pro-duces signs of failure. This effect is

en-hanced by the fact that the coronaries may

be inadequately supplied since they can fill only in diastole.

Clinical Features of Left Ventricular Failure

The clinical signs of left ventricular

fail-ure are most commonly dyspnea, rales in the chest, the presence of gallop rhythm, roentgenographic evidence of congested

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left ventricle begins to fail the venous pres-sure rises behind it distending the left

auni-dc, pulmonary veins and lung fields. When

the right ventricle fails, the venous pres-sure rises in the right auricle, in the great

veins, and in the liver; the edema comes later. While either ventricle may fail alone,

rather commonly both are involved, one predominating over the other. Failure of the left ventricle may soon lead to a rise

in pressure in the pulmonary veins, the pulmonary artery and right ventricle, thus presenting the picture of right heart failure.

In babies with left heart failure cardiac

catheterization may reveal a pressure in the right ventricle and pulmonary artery varying from normal up to systemic levels.

One baby with endocardial fibroelastosis had a pressure in the right ventricle of

100 mm. of mercury.

TREATMENT

The orthopneic position is easily achieved

in older children; it allows ease of breathing and diminishes ‘the pressure in the right

auricle. It is preferable to keep the patient

at an angle of 50 to 60 degrees. In babies

a small gatch bed may be used or a pillow at the back. It is necessary to put a support under the thighs to keep them from sliding

down in bed. At times a restriction jacket

may be helpful providing it does not

inter-fere with breathing. The baby should be turned from side to side at regular intervals

to minimize pulmonary stasis and to

ascer-tam that a comfortable position is being maintained.

DIGrrALIs. It used to be thought that the

chief benefit of digitalis was a direct effect

on the heart rate. It is now generally be-lieved that slowing of the heart is secondary

to restored compensation of the failing or-gan. The only time digitalis appears to have

a direct effect on rate is in certain arrhyth-mias of which auricubar fibrillation is the chief example. Therapeutic doses of digi-talis, therefore, do not slow a normal rapid heart but do so only in the presence of

failure.6

In heart failure the chief effect of

digi-talis is on the myocardium itself. Cattel and Gold7 have shown that it causes an in-creased force of systolic contraction with

more adequate emptying of the heart

re-sulting in improvement of the clinical con-dition of the patient. The exact chemical

mechanism of this beneficial effect is not

yet clarified.

One minor side effect of digitalis is its diuretic action which is independent of its

effect on the heart. Farber8 and Lown and Levine6 have shown that in patients with-out edema, or with noncandiac edema, there

is a slight increase in the salt and water

excretion following its administration.

There are several useful digitalis agents. Lown and Levine6 summarized the various actions of 6 of them. Our chief experience

has been with the digitalis leaf, digoxin and

gitaligin. Digoxmn, we have found, is

par-ticulanly useful in treating infants and chil-dren, since it has a relatively rapid action,

the duration of its effect is shorter than other oral preparations, and its toxic effects, if they appear, are shorter lived. Further-more, the therapeutic effect is reached

con-sidenably before the toxic level is

ap-proached. A 2-year-old brother of one of

our patients swallowed 4 mg. of digoxin, or approximately 4 times the digitalizing dose,

and survived. He was desperately ill for one night and part of the next day; then he improved rapidly.

DOSE. The digitalizing dose of digoxin

for infants and children is .07 mg./kg. (.03 mg./pound), given in 4 divided doses over

24 hours. The daily maintenance dose is one-fifth of the digitalizing dose. A common scale of the daily oral maintenance dose in different ages is as follows:

Small newborn .03 mg.

Large newborn .05 mg.

Few months to 2 yr 12-.18 mg.

3 to 8 yr 20-.25 mg.

8 yr. and up 25-50 mg.

If digitalization is a matter of urgency, the digoxin may be given intravenously, preferably by giving a quarter to a half of the digitalizing dose at the start.

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intrave-nously or by mouth as required. It is

pref-enable to give only a portion of the total

digitalizing dose intravenously initially since there is a vasoconstricting effect with a full digitalizing dose which may

occa-sionally precipitate pulmonary edema in a

patient already in failure.’

Gitaligmn is also a useful preparation since its characteristics are similar to those

of digoxmn. Its dose is essentially the same as slightly larger amounts are well

toler-ated. Both of these preparations have a sig-nificant difference between the therapeutic

and toxic levels, thus making them safe and useful.

In babies and children on the doses

de-scnibed, we have usually found a satisfac-tory digitalis effect with relief of the edema

or evidence of failure. This has usually oc-curned without any signs of digitalis toxicity and frequently without any evidence of digitalis effect on the electrocardiogram.

One cannot but conclude, therefore, that the therapeutic and toxic bevels are spread

fairly widely in infancy and childhood in

the preparations used and the margin of

safety is considerable.

DIGrrALIs Toxicrny. Anorexia, nausea

and vomiting are likely to be early signs of digitalis toxicity and may be followed by

visual symptoms, dizziness and headaches.

There also may be ectopic beats, first de-gree heart block and one may have bundle

branch block or intraventricubar conduction impairment, shortening of the QT interval,

ventricular tachycardia, sinoatrial block and intna-atrial block. These abnormalities are

rare in children on digitalis. Characteristic effect on the electrocardiogram is the

scoop-ing of the ST segment with an inversion of the first portion of the T wave. It should be remembered, however, that digitalis poisoning can occur in the absence of this

electrocardiographic change.

Aunicular fibrillation may be produced

by an overdose of digitalis. We have seen

this occur occasionally in childhood. Stop-ping the digitalis resulted in the return of the heart rhythm to normal.

OXYGEN. Most cyanotic children have

their arterial oxygen saturaton increased by the administration of oxygen. This has been tested on all varieties of congenital heart

disease and almost invariably where there is any desaturation of the arterial blood

there is an increase with oxygen of 10 to 20 per cent, depending on the type of heart defect and the severity of the cyanosis. When there is no unsaturation of the

hemo-globmn in congestive heart failure, it is not likely that oxygen has any beneficial effect.

Oxygen, plastic hoods and incubators should be kept at approximately 50 per

cent saturation. Regular testing of oxygen

content may be necessary: 4 to 5 liters per minute in incubators; 8 to 10 liters in tents,

may be necessary to keep the level at 50

per cent.

Oxygen in high concentrations irritates thus increasing respiratory mucus. Occa-sionally it favors the development of atelec-tasis by washing out the nitrogen in the

pulmonary alveoli.9

In con pulmonale, chronic anoxia and

carbon dioxide retention may be present. The respiratory center thus becomes ac-climatized to the high carbon dioxide and ceases to respond, respirations being

stimu-bated largely by anoxia. Administration of

oxygen may then depress respirations and

carbon dioxide may be retained to an cx-cessive degree causing drowsiness or coma.

The breathing of room air rapidly reverses these effects.

Mimcuaw Diuiu’rics. Edema is not as

common in children with heart failure as in adults and when it does occur it usually

responds to digitalis therapy. There are, however, a number of cases that do not yield to this therapy but are helped by

di-uretics. They are used in conjunction with digitalis and low sodium diet. The ones in

common use are the mercury compounds

(

Mercuhydrmn#{174}, Thiomenin#{174}), purine deri-vatives

(

Theobromine#{174}, Diuretin#{174}), and various salts such as ammonium chloride,

calcium chloride, etc.

The most useful preparation for children is Thiomenin#{174}; it is relatively nontoxic and

(8)

intramuscularly or intravenously. The

fol-lowing dosage has proved effective and satisfactory in infants and children.

Under 1 year 12-.25 ml.

1 to 5 years .25 ml.

5 to 13 years 25- .5 ml.

It may be given every other day for 5ev-eral doses but usually a response will occur promptly and it is best to give the drug

as infrequently as possible.

Diuretin#{174} or Theobromine#{174} are useful preparations because they can be given

by mouth in tablet form. The dose for chil-dren over 5 years for either one is 235 to 450 mg. daily for several days.

Recently, an oral diuretic composed of a

carbonic anhydrase inhibitor capable of

increasing the urinary secretion of sodium has become available. The proprietary name for this preparation is Diamox#{174}. The dose is 5 mg./kg./day.

ELECTROLYTE CHANGES IN CONGESTIVE HEART FAILURE

When a patient with congestive heart failure is given a mercurial diuretic, the

fluid eliminated contains both chloride and sodium, but more of the former than of the latter. Potassium or ammonium is excreted in place of sodium. The loss of chloride

may produce alkalosis with a rise in serum

bicarbonate and a fall in chloride. Such hypochboremic alkalosis rarely produces

symptoms in itself in a child but it may cause a lack of response to further

men-cunial diuretics. Correction of the alkalosis restores the responsiveness to mercury. The routine use of ammonium chloride with the

administration of mercurial diuretics will

usually prevent resistance from occurring.

Hyponatremia (Low Salt Syndrome)

The difference between this condition and hypochloremia is that both sodium and

chloride are reduced in the low salt syn-drome. These patients appear more ill, are weaker than might be expected. They are often drowsy and anonexic, and if the con-dition continues, it may lead to circulatory

collapse. This clinical picture may be pro-duced by excessive mercurial diuresis, vom-iting and diarrhea, abdominal paracentesis,

or it may occur spontaneously with no

obvi-ous cause.

In children with congestive heart failure the low salt syndrome is a rare development

but should be considered when there are

etiologic factors in operation that might lead to its appearance.

Respiratory Acidosis

When there is lung pathology present with reduced pulmonary ventilation, there may be a retention of carbon dioxide with high blood bicarbonate resulting in lowered

plasma chloride. The blood becomes more

acid, this being revealed by a lowered pH. This differentiates it from metabolic

alka-losis. An electrolyte picture such as this may develop in con pulmonale cases with

congestive heart failure. The treatment is

best directed against the underlying cause

of the pulmonary hypertension or lung

in-volvement.

Potassium depletion may occur with

cx-cessive mercurial diuresis or with prolonged

administration of cortisone. The chief im-pontance of a lowered potassium in

con-gestive heart failure is in association with

digitalis intoxication. Friedman10 has shown

that potassium exerts an antagonistic effect on digitalis activity. A lowered potassium allows a greater digitalis effect.

Potassium salts should be given by mouth

in the presence of arrhythmias associated

with potassium depletion

(

1 gm. daily to

a child).

DIET AND FLUID INTAKE

In adults a low sodium diet has proven to be most helpful in cleaning edema. The normal diet contains approximately 5 to

12 gm./day. A reduction to 0.5 to 1.0 gm. daily diminishes the sodium content of the

tissues to a degree that will largely prevent

excessive fluid retention in the body.11’ 12

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since this provides a low sodium content,

it is very suitable for all children with cardiac failure and fluid depletion. If

men-cunial diuretics are given with a low sodium diet, they should be given somewhat cau-tiously so as to avoid too great a depletion

of sodium in the body. The blood chemistry should be checked under such

cincum-stances.

For babies a preparation of powdered milk with a low sodium content is

availa-ble (Lonalac#{174}). This is useful if the edema is obstinate and does not respond to

digi-talis therapy.

The fluid intake does not need to be re-stricted in infants and children. They are

allowed the fluid quantities they wish to take unless more fluids are indicated.

PULMONARY EDEMA

Fortunately, pulmonary edema is un-common in babies or older children. When it does occur, it is best treated with: (1) orthopneic position; (2) morphine, 1 mg. per year of age; (3) oxygen, or (4)

oxy-gen bubbled through 50 per cent ethyl alcohol, administered for 10 minutes at a

time and repeated every 20 to 30 minutes

as required.

PROGNOSIS

In a review of 332 instances of failure at the Hospital for Sick Children, Toronto, it was found that 85 per cent died. In

evaluat-ing the prognosis of any particular case there are a number of influential factors

that appear.

CAUSE OF The underlying

de-feet may be successfully treated either medically or by surgical correction. When

such is the case the prognosis may be good, as in coarctation of the aorta. When no

medical therapy is of avail and surgical con-rection is so far impossible, the prognosis

is poor, as in aortic atresia.

The degree of failure influences prog-nosis. Those with rapid onset of severe

failure in infancy have a poorer outlook than those that have a milder degree com-ing on more slowly.

Age of Onset in Relation to Failure

The age at onset has obvious prognostic implications. The outlook is poorer if the

onset is in the first week or month of life. Bnrni TO 1 WEEK: Among those that have

the onset of signs and symptoms of failure in the first week of life, 85 per cent died

in the next weeks or month. These include aortic atresia, transposition of the great vessels, and coarctation of the aorta, in

that order.

1 Wiucic TO 1 Morm: When the onset of failure occurs between 1 week and 1 month, 66 per cent will die in the near

future. Coarctation of the aorta predomi-nates in this group; transposition of the

great vessels is second; endocardial fibro-elastosis is third.

1 TO 2 MoNms: When the age of onset

is 1 to 2 months, 58 per cent die shortly.

The leading cause of death from failure is transposition of the great vessels, with

endocardial fibroelastosis second, and co-arctation of the aorta third. Atrioventricu-laris communis is fourth and paroxysmal

tachycardia fifth.

2 TO 6 MoNms: When the age at onset

of failure is 2 to 3 months after birth, 50 per cent will die shortly. Endocardial

fibro-elastosis is the leading cause of death. Transposition of the great vessels is second, total anomalous venous drainage into the right auricle or its tributaries third, and

ventricular septal defect fourth.

6 TO 12 MoNms: In the second half of

the first year endocardial fibroelastosis is a

leading cause of death from heart failure. Ventricular septal defect is second.

1 TO 10 Y&ns: After the first year of life

a variety of conditions cause heart failure but they only comprise 10 per cent of the total. Of those that do develop heart failure

in this age group, 40 per cent die in the

next few months or in a year or two. This group includes ventricular septal defect, auricular septal defect, atrioventnicularis

communis, paroxysmal tachycardia, myo-carditis, rheumatic heart disease and

ane-mia.

(10)

electro-cardiogram is of some prognostic

signifi-cance. Of those with failure that showed

right ventricular hypertrophy 78 per cent died shortly, whereas among those with left ventricular hypertrophy the mortality was

44 per cent. When evidence of both right and left ventricular hypertrophy was pres-ent, the mortality was 60 pen cent.

When right ventricular hypertnophy is present, there is a slightly higher mortality

among those with a qR pattern in the right precordial leads than when this sign is backing (84 per cent as compared with 60 per cent).

ASSOCIATED RESPIRATORY INFECrION.

When congestive heart failure in infancy is associated with, or precipitated by, a

respiratory infection, the mortality is lower than when the failure has occurred spon-taneously from the underlying defect alone. The infection can usually be treated

sue-cessfubly. This, coupled with therapy for the failure, causes the signs of failure to disappear completely.

ACKNOWLEDGMENT

The author wishes to express his

appre-ciation to Dr. Geoffrey Watson for his help in collecting some of the data used in the

preparation of this paper.

REFERENCES

1. McMichael,

J.

: Dynamics of heart failure. Bnit. M.

J.,

2:525 and 578, 1952.

2. Hope,

J.

: A Treatise on the Diseases of the Heart and Great Vessels. London, Wil-ham Kidd, 1832.

3. Mackenzie,

J.

: Diseases of the Heart, 3rd

Ed. London, H. Frowde, 1914.

4. White, P. D. : Heart Disease, 4th Ed. New York, Macmillan, 1951.

5. Wilson, M. G. : Rheumatic Fever. New York, Commonwealth Fund, 1940. 6. Lown, B., and Levine, S. A. : Current

Con-cepts in Digitalis Therapy. Boston, Little,

1954.

7. Cattell, M., and Gold, H. : Influence of digitalis glucosides on force of contrac-tion of mammalian cardiac muscle.

J.

Pharmacol. & Exper. Therap., 62:116, 1938.

8. Farber, S.

J.,

Alexander,

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D., Pellegrino, E. D., and Earle, D. P. : The effect of intravenously administered digoxin on

water and electrolyte excretion and on

renal functions. Circulation, 4:378, 1951. 9. Altschule, M. D. : Hazards in the treatment

of cardiac decompensation, Mod. Con-cepts Cardiovas. Dis., 22:190, 1953. 10. Friedman, M., and Bine, R., Jr. :

Observa-tions concerning the influence of potas-sium upon action of digitalis glycoside (lanatoside C). Am.

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M. Sc., 214:633, 1947.

11. Schroeder, H. A. : Studies on congestive heart failure. I. The importance of re-stniction of salt as compared to water.

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1956;18;491

Pediatrics

John D. Keith