AORTIC
STENOSIS
IN
INFANCY
Bernard H. Feldman, LT. M.C., USN, and
Lewis P. Scott, Ill, LCDR, M.C., USN
Department of Pediatrics and Cardiology, U.S. Naval Hospital, National Naval Medical Center, Bethesda, 14, Maryland
(Submitted September 13; accepted for publication December 2, 1963.)
The opinions expressed and the assertions made are those of the authors and are not to be construed
as official or reflecting the views of the Navy Department or of the Naval Service at large.
PEDIATRICS, June 1934
931
T
u CLINICAL management of congenitalaortic stenosis taxes the skills of even
the most astute clinician. The handling of
the individual infant is made difficult not
only because the criteria for surgical
inter-vention have not been well developed, but
also because the threat of sudden death
exists even during the first year of life. The
purpose of this communication is to present
the case histories of four infants with aortic
stenosis in order to demonstrate the wide
spectrum of the disease and to emphasize
the problems encountered in management
during this critical first year. Guidelines are
suggested for assessing the severity of the
aortic obstruction and need for surgical
in-tervention. The suggestions offered are
based on a limited clinical experience,
hence further experience may dictate a
change in these recommendations.
Case I
CASE REPORTS
G.L, a 6-week-old male had a cardiac murmur detected at birth. Growth and development had proceeded normally.
Physical examination revealed a healthy infant
with weak peripheral pulses. Auscultatory pres-sures could not be obtained but flush pressures revealed no gradient between upper and lower
extremities. A thrill was palpable at the left lower
sternal border and the heart was of normal ac-tivity. The second sound was single and of normal intensity at the base. A loud constant ejection click was present at the apex. A Grade IV rough
stenotic systolic murmur was loudest at the 4th
left intercostal space and radiated well to the 2nd right intercostal space and to the back. There was no evidence of congestive heart failure.
Roentgenograms showed a heart of normal size and configuration. Pulmonary vasculature was normal. An electrocardiogram demonstrated a
mean electrical axis of +600. Deep S waves over
the right side of tile chest with normal R waves over the left side, in a six-week-old infant,
sug-gested left ventricular hypertrophy (Fig. lb).
When seen again at 8 weeks of age, a history
of trachypnea and a suggestion of orthopnea with
feedings was elicited. Physical examination was unchanged except for rapid respirations. A chest roentgenogram showed definite transverse
enlarge-ment of the cardiac silhouette with passively
con-gested lung fields (Fig. la). An electrocardiogram revealed further evidence of left ventricular
hyper-trophy and the evolution of a strain pattern
(Fig. lb).
The infant was hospitalized and digitalized with Digoxmn .04 mg per pound per 24 hours. Clinical improvement was excellent in that the respiratory rate slowed and the cardiac silhouette decreased
in diameter. Cardiac catheterization was
con-sidered but deferred because of the good clinical
response. On the 9th day of hospitalization, while
awaiting discharge, the infant was found lifeless. Postmortem examination showed marked left yen-tricular hypertrophy. A severely obstructed,
dome-shaped aortic valve with a central opening of
2.5 mm in diameter was the only defect noted.
Case II
R.R., a male, was first seen at 3 weeks of age
for evaluation of a heart murmur detected the first day of life. Growth and development had been normal.
Physical examination revealed a pale, tachvpneic
infant weighing 13 lb 15 oz. The peripheral pulses
were diminished in volume and there was no delay in femoral pulsations. Systolic blood pressure in the right arm was 90 mm Hg. A left ventricular
impulse was palpable as well as a faint thrill at the lower left sternal border. The second sound
was normal. A prominent third sound and a con-stant ejection click were heard at the apex. A Grade IV stenotic systolic murmur was heard at the lower
left sternal border and transmitted to the 2nd
right intercostal space, the right neck, and the back. Hepatosplenomegaly was not present.
electrocardio-The patient was hospitalized for two weeks and
digitalized with Digoxin 0.04 mg per lb per 24 hours. A persistent anemia responded to iron therapy. He was followed at weekly intervals
thereafter and gained weight normally. By 5 months of age his heart rate gradually slowed.
At 6 months of age tachypnea disappeared and
regression of cardiomegaly was first noted. An
electrocardiogram showed persistent left
yen-tricular hypertrophy and digitalis effect. At 18
months of age the child was still doing well.
Case Ill
M.W., a 6-month-old female, was admitted to the hospital following an episode of what was
Fic. la. X-ray (G.L.) at 8 weeks interpreted show- thought to be paroxysmal supraventricular
tachy-ing cardiomegaly as well as a large thyrnic cardia. A heart murmur had been detected at birth
shadow. but the child grew and developed normally and
remained completely asymptomalic. A diagnosis
of aortic stenosis had been made previously by another physician.
On the day of admission the mother found the infant in bed, ashen gray, lethargic, and hypo-tonic. The child was taken to another facility
where she was found to have a pulse rate of 200 per minute. Transfer to the N.N.M.C. was effected
before obtaining an electrocardiogram. During the
Fic. lb. ECG showing left ventricular hypertrophy with development of “strain” pattern over a 2-week period. Tracing was obtained prior to
digitalis therapy.
gram revealed a mean electrical axis of +90#{176},
voltage criteria of left ventricular hypertrophy,
and flattening of the T wave in lead AVF but no
S-T or T wave changes in the left chest leads
(Fig. 2b). FIG. 2a. X-ray (R.R.) showing marked
cardio-Aortic stenosis was suspected but a ventricular megaly. septal defect could not be ruled out because of
the location of the thrill and murmur and the enlargement of the heart. Direct left heart punc-ture under general anesthesia confirmed the diag-nosis of aortic stenosis (Table I). An elevated left ventricular end diastolic pressure suggested failure
of the ventricle. The aortic pulse tracing showed a
delayed upstroke of 0.2 seconds and an early
ana-erotic notch both of which suggested moderately
severe aortic stenosis. During the procedure marked
systemic hypotension developed. Thus, the
meas-ured gradient was not a true reflection of severity Fic. 2b. ECG with voltage criteria for left
in so far as an accurate estimation of cardiac out- ventricular hypertrophy. Note normal T wave in
Case II (R.R.) RA RV PA LV Ao 61.8 58.0 60.6 96.1 6 25/-25/11 66/14 41/29
Case 111 (MW.)
RA RV PA LV Ao 54.1 59.7 62.6 97.2
transfer her pulse slowed to 130 per minute. Physical examination upon admission revealed a well-nourished, comfortable infant. Pulse volume was slightly diminished and blood pressure was
88/- in the right arm. No thrills were present.
Abnormal cardiac findings included a loud
con-stant ejection click at the apex and lower left
sternal border as well as a Grade III stenotic
systolic murmur heard best in the 2nd right inter-costal space with transmission to the neck, the
it(’X, and the back.
The cardiac silhouette and pul11onary
vascula-ture were normal on a chest roentgenogram
(Fig. 3a). An electrocardiogram demonstrated a mean electrical axis of +75#{176} with no evidence of
left ventricular hypertrophy (Fig. Sb).
Cardiac catheterization revealed aortic valvular
obstruction. The gradient was 22 mm Hg with a normal cardiac output (Table I). Subsequently the child has been followed closely in the
out-patient department. At 26 months of age she weighed 25 lb and was asymptoniatic. The only change in the physical findings has been the development of a single second sound which may indicate increasing severity. Serial electrocardio-grams have remained unchanged.
Case IV
K.C., a 6-month-old female, was referred for evaluation when a heart murmur was detected during a well-baby examination. Growth and
development had been uncomplicated.
Physical examination revealed a healthy infant
who weighed 15 lb 12 oz. Peripheral pulses were normal and there was no lag in the femoral pulsa-tions. Left ventricular activity was increased and
TABLE I CATHETERIZATION DATA Catheter Position Oxygen sat.
(%)
Pressure (mm Hg) Q0/0 Us/o 144/0Fic. 3a. X-ray (M.\V.) showing normal heart size with dilatation of ascending aorta.
FIG. 3b. ECG within nornial limits.
a thrill was palpable at the lower left sternal
border. The second heart sound was
physiologi-calls’ split and a constant ejection click was heard at the apex. A Grade III stenotic systolic murmur was present at the lower left sternal border with transmission to the 2nd right intercostal space, the neck, and the back. Congestive heart failure
was not present.
Chest roentgenograms showed the cardiac sil-houette and pulmonary vasculature to be normal
(
Fig. 4a). An electrocardiogram revealed a meanelectrical axis of +60#{176}and the height of the R
wave over the left precordium was at the upper
limits of normal (Fig. 4b).
The infant has been re-evaluated at periodic intervals. Physical findings and electrocardiograms have remained unchanged and the patient has
continued with normal growth and development.
COMMENT
The average death rate in childhood from
congenital aortic stenosis is 75%1
Cumula-tive data from several series2 in which the
age of death is given reveals that of the
childhood deaths, 35% occurred during the
first year of life; 27% from the first to the
tenth year; and 38% from tile tenth to the
sixteenth year. Adolescence, with its
Fic. 4a. X-ray (K.C.) showing normal heart size.
Fic. 4b. ECG showing R wave over left chest at
upper limits of normal.
period of greatest risk. It is obvious from
these mortality statistics that complacency
during the pre-adolescent years is not
justi-fied for death is not related to age but
rather to severity of obstruction.
In the newborn period, closure of the
ductus arteriosus results in an increased
workload on tile left ventricle. Normally
this increased load is accompanied by a
gradual thickening and hypertrophy of the
left ventricle. The presence of left
ventricu-lar outflow obstruction, whether distal as
in coarctation of the aorta or proximal as
in aortic stenosis, may be sufficient
addi-tional stress to cause failure of the ventricle.
Beyond infancy congestive heart failure
a!-most never occurs. Instead, death may
oc-cur suddenly presumably due to ventricular
arrhythmias.
It is incumbent upon the pediatrician to
detect critical stenosis at any age period. In
an infant with a lower left sternal border
systolic murmur, a thrill, diminished pulse
volume, and left ventricular hypertrophy on
the electrocardiogram, one should suspect
aortic stenosis. In the presence of
cardio-megaly and congestion of the lungs, the
diagnosis of a ventricular septal defect is
suggested. An apical diastolic murmur
would make the diagnosis of ventricular
septal defect more likely. However, only
after digitalization will the more
character-istic features of each lesion become
ob-vious.8
In an infant in whom a clinical diagnosis
of aortic stenosis has been made, the
fol-lowing features suggest severe obstruction:
(1) Electrocardiographic changes of left
ventricular hypertrophy with S-T and T
wave changes prior to digitalis therapy. (2)
Congestive heart failure which is mainly
left-sided with dyspnea, rales, and
roent-genographic evidence of cardiac
enlarge-ment and pulmonary congestion. (3)
Di-minished volume of peripheral pulses in all
extremities in the absence of overt
con-gestive failure. (4) Syncope.
Other symptoms related to obstruction
such as fatigue, chest pain, and abdominal
pain, important in older children, are
sub-jective in nature and cannot be accurately
interpreted in infants. Of the objective
find-ings listed above, the strain pattern on the
electrocardiogram is the most reliable and
when present usually denotes critical
steno-sis. However, when any of these findings
are manifest further investigation with
car-diac catheterization is necessary.
The technical difficulties encountered
plus the critical condition of many of these
infants renders cardiac catheterization an
extremely hazardous procedure. Initially,
right heart catheterization should be
per-formed from the leg, and the catheter
passed, if possible, across a patent foramen
ovale into the left atrium and left ventricle.
Simultaneous measurement of left
ventricu-lar and systemic arterial pressures will then
provide a satisfactory estimate of the aortic
obstruction. If one is unable to cross the
atrial septum with a catheter then
retro-grade femoral arterial catheterization is
performed. In our experience this procedure
has not been very successful because of the
manipu-lating the catheter around the arch to the
aortic root. If the foregoing methods fail,
general anesthesia is administered and a
transthoracic apical left heart puncture is
performed. Left ventricular pressure is
measured directly while aortic pressure is
simultaneously measured through the
in-dwelling aortic catheter.
That careful repeated clinical
observa-lions are necessary in caring for infants
with aortic stenosis is well demonstrated by
the course of the first patient (G.L.)
Be-tween the 6th and 8th weeks of life, subtle
but definite signs of congestive heart failure
developed and a left ventricular strain
pat-tern evolved in the electrocardiogram.
Clinical improvement with anticongestive
measures was observed. Failure to
appreci-ate the significance of the
electrocardio-graphic changes resulted in postponement
of cardiac catheterization. Had the infant
been catheterizezd the severity of
obstruc-tion would have been revealed and surgery
performed.
In the second patient (R.R.), severe aortic
stenosis was suspected and catheterization
was performed. The procedure proved the
diagnosis but did not provide an accurate
assessment of the severity of obstruction.
Although it is recognized that critical aortic
stenosis can exist without a strain pattern,
this is by no means a common occurrence.
Thus the absence of a strain pattern in our
patient as well as the gradient measured at
catheterization was interpreted as
indicat-ing that the obstruction was less than
criti-cal. Accordingly, conservative therapy was
continued and surgery was postponed. It is
hoped that with further growth a more
ade-quate surgical procedure can be performed.
It is likely that the clinical response in this
infant parallels that seen in an infant with
severe coarctation of the aorta with
con-gestive heart failure. Judicious use of digitalis and the eventual development of
left ventricular hypertrophy gradually bring
the congestive heart failure under control.
Of interest was the effect on the heart
fail-ure of the “physiologic” anemia of infancy.
Careful use of packed red cell transfusions
and iron therapy may be important
de-terminants influencing the eventual
out-come of a critically ill infant.
The third patient (M.W.) experienced
what was probably an episode of
supraven-tricular tachycardia simulating a syncopal
attack. Although the physical findings were
those of mild aortic stenosis, the occurrence
of this episode necessitated cardiac
catheter-ization to determine the severity of
obstruc-tion. The clinical impression of mild aortic
stenosis was confirmed and the patient has
continued to do well.
In the fourth patient (K.C.), the presence
of an ejection click as well as the quality,
location, and transmission of the murmur
were compatible with aortic stenosis. The
intensity of the murmur suggested mild
obstruction. Although the
electrocardio-gram suggested early left ventricular
hy-pertrophy, criteria for cardiac
catheteriza-tion were not fulfilled. This child will be
followed at frequent intervals at which time
serial electrocardiograms and
roentgeno-grams will be obtained.
CONCLUSIONS
We conclude that the principles of
con-genital aortic stenosis stated by Reynolds Ct
al.1 for children apply equally well to infants.
The hazards and uncertainties of left heart
catheterization in this age group make
care-ful clinical evaluation and strict criteria for
its performance a necessity. The strain
pat-tern of the electrocardiogram is the single
most important determinant of therapy and
when present usually indicates critical
stenosis requiring cardiac catheterization
and surgical relief. Infants with congestive
heart failure in the absence of a strain
pat-tern may be treated with anticongestive
measures in an effort to postpone surgery.
Infants with aortic stenosis, in the absence
of strain, cardiomegaly, and diminished
pulse volume need not be catheterized and
should be followed initially at 2-4 week
intervals with close attention to the
electro-cardiogram.
The surgical relief of severe aortic
1. Reynolds, J. L., Nadas, A. S., Rudolph, A. NI.,
transaortic approach utilizing vena caval
occlusion with hypothermia or
cardiopul-monary by-pass. The reported risks
en-countered with surgery vary considerably.
Cooley#{176}reports only one death in 11
opera-tions. No preoperative clinical or laboratory
data are presented that would indicate the
severity of the aortic lesion. On the other
hand, in smaller series10” of critically ill
infants, operative mortality figures are in
excess of 50%. Thus the physician charged
with caring for the infant with aortic
steno-sis must carefully evaluate the signs of
sev-erity as well as previous surgical experience
before recommending operative
interven-tion.
SUMMARY
1. Four infants with congenital aortic
stenosis of varying severity have been
pre-sented.
2. Clinical findings of severity include
congestive heart failure, diminished pulse
volume, and electrocardiographic evidence
of left ventricular hypertrophy and strain.
3. Congestive heart failure which
re-sponds to digitalis therapy is not, in itself,
a criterion for surgical intervention in
in-fancy.
4. The presence of left ventricular
hyper-trophy and strain usually indicates the need
for surgical intervention.
REFERENCES
et a!.: Critical congenital aortic stenosis with minimal electrocardiographic changes.
New Engl. J. Med., 262:276, 1960.
2. Ongley, P. A., Nadas, A. S., Paul M. Fl., et al.: Aortic stenosis in infants and childen.
PEDIATRICS, 21:207, 1958.
3. Braverman, I. B., and Gibson, S. : The
out-look for children with congenital aortic
stenosis. Amer. Heart J., 53:487, 1957. 4. Marquis, R. NI., and Logan, A. : congenital
aortic stenosis and its surgical treatment. Brit.
Heart J., 17:373, 1955.
5. Morrow, A. G., Sharp, E. H., and Braun-wald, E. : Congenital aortic stenosis: Clinical
and hemodynamic findings, surgical tech-nique, and results of operation. Circulation,
18: 1091, 1958.
6. Kieth, J. D., Rowe, R. D., and Vlad, P.:
Heart Disease in Infancy and Childhood. New York: Macmillan, 1958, p. 195.
7. Kjellberg, S. R., Mannheimer, E., Rudhe, U.,
et a!.: Diagnosis of Congenital Heart Dis-ease: A Clinical and Technical Study by the
Cardiologic Team of the Pediatric Clinic,
Karolinska Sjukhuset, Stockholm. Chicago: Year Book Publishers, 1955, p. 496.
8. Bicoff, J. L., Thompson, W., Arbeiter, H. I.,
et al.: Severe aortic stenosis in infancy.
J. Pediat., 63:161, 1963.
9. Cooley, D. A., Berman, S., Santibanez-Wool-rich F. A.: Surgery in the newborn for con-genital cardiovascular lesions. J.A.M.A., 182:
912, 1962.
10. Lees, M. H., Hauck, A. J., Starkey, C. W. B.,
et al.: Congenital aortic stenosis: Operative indications and surgical results. Brit. Heart
J. 24:31, 1962.
11. Lillehei, C. W., Levy, M. J., Varco, R. L.,
