DIAGNOSIS AND TREATMENT

THE “INCIDENTAL” SYSTOLIC MURMUR

Arthur J. Moss, M.D.
From the Department of Pediatrics, UCLA School of Medicine, Los Angeles

T HE CHILD with symptomatic heart dis- dance with the classification of Levine and
ease is not generally much of a prob- rv2 Grade I-very faint, audible only
lem for the practicing pediatrician. He is after a period of careful auscultation.
promptly referred to a cardiac center or to Grade Il-faint but audible immediately.
a pediatric cardiologist for further evalua- Grade 111-of moderate intensity. Grade IV
lion. However, such is not the case with the -loud and often accompanied by a thrill.
asymptomatic child in whom a systolic Grade V-extremely loud but cannot be
murmur is heard incidentally during the heard with the stethoscope off the chest
course of a routine physical examination. wall. Grade VI-extremely loud, can be
This very COI111TUOfl event requires that the heard with the stethoscope off the chest
pediatrician decide in each instance wall.
whether the murmur can be safely ignored Since the intensity of the murmur is in-
or whether further studies are indicated. fluenced by cardiac output, it is important
For a detailed description of murmurs in to auscultate the heart with the child at rest
childhood, the reader is referred to the ex- and while free of fever. Anything which in-
cellent work of Castle and Craige.’ creases cardiac output ( exercise, fever, ane-
The overwhelming majority of systolic mia, anxiety, hyperthyroidism, and so
murmurs discovered in asymptomatic chil- forth) may intensify an existing murmur or
dren are either innocent or are caused by a even produce one. Conversely, the intensity
ventricular septal defect. The present dis- of the murmur may almost disappear or
cussion is limited to the two most common completely disappear while crying because
innocent murmurs, the vibratory and the of the effect of the Valsalva maneuver on
pulmonic ejection murmur, and their differ- pressure relationships and blood flow. It is
entiation from murmurs due to ventricular also important to recognize that, in the very
septal defect, mitral insufficiency, and other young infant, organic murmurs may mi-

organic lesions. The venous hum, also a fre- tially be barely audible and reach Grade
quently encountered innocent murmur, is III or IV intensity only after several days or
not included because it is easily recogniz- weeks. This results from the changing pres-
able by the louder diastolic component, the sure relationships which arise from postna-
location over the base of the heart, and the tal transition of fetal to adult-type pulmo-
characteristic diminution in intensity or nary vasculature. With the development of
complete disappearance with compression the adult type of pulmonary vessels, the
of the neck vessels, with movement of the high pulmonary vascular resistance present
head from side to side, or when the patient at birth recedes, and shunts between the
lies down. It is sometimes confused with two circulations may become larger.
the murmur of patent ductus arteriosus;
but, because of the foregoing features and
THE VIBRATORY MURMUR
because it is usually located parasternally This murmur is commonly encountered
to the right rather than to the left, the dif- in pediatric practice. The exact means by
ferentiation is not difficult. which it is produced remains uncertain. It
occupies early and mid-systole, is maximal
INTENSITY OF MURMURS
at the third and fourth left intercostal
For the purposes of this discussion, the spaces, and extends laterally to the apex of
intensity of the murmur is graded in accor- the heart. It is of low or moderate intensity

ADDRESS: Department of Pediatrics, UCLA School of Medicine, Los Angeles, California 90024.

PEDIATRICS, Vol. 45, No. 4, April 1970

687

Downloaded from by guest on October 11, 2016

688 SYSTOLIC MURMUR

(not more than Grade III ) and is charac- THE PULMONIC EJECTION MURMUR
terized by a uniform, low-pitched sound This common, innocent murmur is due to
which has been described as musical, turbulence in the outflow tract of the right
twanging string, fiddle string, or groaning ventricle, normally associated with right
in character. This quality is best appre- ventricular ejection. It is located in the see-
ciated with the bell of the stethoscope. ond or third left intercostal space paraster-
Typically, the murmur diminishes or disap- nally and is early to mid-systolic in time. It
pears when the patient is examined in the ranges in intensity from Grade I to Grade
upright position. III. It results from any condition which
Occasionally, the musical quality is not causes an increase in pulmonary blood flow
detected and then the murmur may be con- ( anemia, fever, anxiety, exercise, and so
fused with that of a ventricular septal de- forth). The identical murmur may be
feet or mitral insufficiency. In addition, the caused by an atrial septal defect or by mild
murmur of cardiomyopathy with or without pulmonic stenosis.
left ventricular obstruction may be of the One should become suspicious of an
vibratory type and may be indistin- atrial septal defect if the
murmur is ejection
guishable on the basis of auscultation from associated with a second sound in the pul-
the innocent variety.3 monic area which is widely split and re-
The murmur of the ventricular septal de- mains so during expiration as well as inspi-
feet, in its typical form, occupies all of sys- ration. The most important diagnostic aus-
tole. It is generally Grade III or more, is cultatory feature is the presence of an early,
widely transmitted, and is often associated short diastolic murmur along the lower left
with a palpable thrill. In the event of spon- sternal border. When present, this murmur
taneous closure, it may become progres- is caused by increased flow through the tn-
sively softer and limited more and more to cuspid valve ( relative tricuspid stenosis).
early systole. With advanced pulmonary hy- A Grade I systolic murmur as an isolated
pertension, the murmur also may be fainter finding ( normal heart tones, no cyanosis,
and may occupy only a portion of sys- and so forth ) can generally be ignored with
tole. Such a murmur, when accompanied by relative safety. Many practitioners elect to
a loud single second sound in the pulmonic disregard the vibratory murmur with the
area, should make one suspicious of ventric- characteristic musical quality, rather than
ular septal defect with pulmonary hyper- worry the family or put them to the ex-
tention. pense of additional studies. Although the
The murmur of mitral insufficiency is practitioner may disregard the vibratory
blowing and high pitched in character and murmur, he should be aware of the calcu-
generally occupies all of systole. Less fre- lated risk (very small indeed ) of overlook-
quently, it may be limited to late systole. In ing an organic lesion. A persistent Grade II
contrast to the vibratory or ventricular sep- or III murmur of questionable origin is in-
tal murmur, it is maximal at the apex or in dictation for an electrocardiogram and tele-
the axilla. This is the major differential fea- roentgenogram. If these are normal, the
tare. possibility of significant cardiomyopathy or
The murmur, which may be associated atrial septal defect is pretty well excluded.
with cardiomyopathy, often cannot be dif- Moreover, although a normal electrocar-
ferentiated on the basis of physical exami- diogram and teleroentgenogram are not in-
nation from a non-organic murmur or from consistent with mild puirnonic stenosis or
a ventricular septal defect. This rare entity mild ventricular septal defect, the risk in-
is often associated with functional obstruc- volved in overlooking either of these is not
tion of the left ventricle. It is insidious in great. Surgical intervention is not indicated
onset and often is not recognized until early in the former and probably not indicated in
adulthood. It is a potentially serious condi- the latter lesion. In a recent survey, 95% of
tion which can cause sudden death. 154 pediatric cardiologists who were asked

Downloaded from by guest on October 11, 2016

 DIAGNOSiS AND TREATMENT 689

whether they would recommend operative seven precordial leads ( V3 in addition to

closure of a small ventricular septal defect V,-V6 ). A small precordial electrode must
(left-to-right shunt, less than 1.5: 1 ) in a 5- be used and care taken not to smear the
year-old child responded in the negative.’ electrode paste from one precordial site to
This change in attitude arises from increas- another. The tracing should be interpreted
ing evidence of spontaneous closure.5 The by one thoroughly familiar with the criteria
major reason for the definitive diagnosis of as they apply to children.
mild pulmonic stenosis or of a small yen- The roentgenogram should be taken with
tricular septal defect would seem to be the the tube about 6 ft from the body. A single
need for prophylactic antibiotics with posteroanterior view is usually sufficient.
bacterial infections or surgical procedures Fluoroscopy in the routine roentgenograph-
which predispose to bacterial endocarditis. ic examination of the heart is not advisable
In the case of atrial septal defect, early rec- because of the excessive radiation.
ognition is quite important because this le- The question of which patients should be
sion is ideally repaired at about 4 years of referred to a pediatric cardiologist depends
age. A delay to adolescent or adult life may upon the competence and experience of the
be accompanied by a signfficant rise in op- pediatrician. If he can establish with confi-
erative risk. dence that a child has an innocent murmur,
The murmur of mild pulmonic stenosis then, of course, there is no need for consul-
may be indistinguishable by auscultation tation. If he is confident that the child has
from the innocent pulmonary ejection mur- mild pulmonic stenosis or a small ventricu-
mur or from that of an atnial septal defect. lar septal defect with unequivocal normality
With mild pulmonary obstruction, the see- of the electrocardiogram and teleroentgen-
ond sound in the pulmonic area is not di- ogram, he would not risk much by contin-
minished in intensity as it is in the more Se- ued observation. In general, it would seem
vere forms. Wide splitting, which varies wise to seek consultation for all children in
with respiration, is said to favor the diagno- whom there is reasonable suspicion that an
sis of mile pulmonic stenosis, but this split- organic lesion might be present.
ting is often encountered in normal chil-
REFERENCES
dren.
1. Castle, R. F., and Craige, E. : Auscultation of
MANAGEMENT OF THE “INCIDENTAL” the heart in infants and children. Pr.rwrmcs,
26:511, 1960.
SYSTOLIC MURMUR
2. Levine, S. A., and Harvey, W. P.: Clinical Aus-
It goes without saying that any child cultation of the Heart. Philadelphia: W. B.

with a systolic murmur deserves the benefit Saunders, p. 196, 1949.

3. Bloomfield, D. K., and Liebman, J. : Idiopathic
of a complete physical examination. This
cardiomyopathy in children. Circulation,
must include palpation of the peripheral 27:1071, 1963.
pulses, measurement of blood pressure in 4. Moss, A. J. : Conquest of the ventricular septal
both upper extremities and one lower ex- defect . . . . A period of uncertainty. Amer. J.
tremity, and careful palpation and auseulta- Cardiol., in press.
tion of the heart. If the patient is febrile or 5. Bloomfield, D. K. : The natural history of yen-
tricular septal defect in patients surviving in-
severely anemic, he should be re-evaluated fancy. Circulation, 34:914, 1964.
when in a state of normal cardiac output. 6. Liebman, J. : Electrocardiography. In Moss, A. J.,
A murmur with intensity of Grade IV or and Adams, F. H.: Heart Disease in Infants,
more is indication for an electrocardiogram Children and Adolescents. Baltimore: Wil-
hams and Wilkins, pp. 199-220, 1968.
and teleroentgenogram. The electrocardio-
7. Adams, F. H., and Rigler, L. C. : Reduction of
gram should include the three standard radiation in children. Circulation, 30:161,
limb leads, the three unipolar leads, and 1964.

Downloaded from by guest on October 11, 2016

 THE "INCIDENTAL" SYSTOLIC MURMUR
Arthur J. Moss
Pediatrics 1970;45;687
Updated Information & including high resolution figures, can be found at:
Services /content/45/4/687
Permissions & Licensing Information about reproducing this article in parts (figures, tables)
or in its entirety can be found online at:
/site/misc/Permissions.xhtml
Reprints Information about ordering reprints can be found online:
/site/misc/reprints.xhtml

PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly publication, it
has been published continuously since 1948. PEDIATRICS is owned, published, and trademarked by the
American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Grove Village, Illinois, 60007.
Copyright © 1970 by the American Academy of Pediatrics. All rights reserved. Print ISSN: 0031-4005.
Online ISSN: 1098-4275.

Downloaded from by guest on October 11, 2016

 THE "INCIDENTAL" SYSTOLIC MURMUR
Arthur J. Moss
Pediatrics 1970;45;687

The online version of this article, along with updated information and services, is located on
the World Wide Web at:
/content/45/4/687

PEDIATRICS is the official journal of the American Academy of Pediatrics. A monthly publication,
it has been published continuously since 1948. PEDIATRICS is owned, published, and trademarked
by the American Academy of Pediatrics, 141 Northwest Point Boulevard, Elk Grove Village,
Illinois, 60007. Copyright © 1970 by the American Academy of Pediatrics. All rights reserved. Print
ISSN: 0031-4005. Online ISSN: 1098-4275.

Downloaded from by guest on October 11, 2016