Carl J. Marienfeld, M.D., Norman TeIles, M.D., Jack Silvera, M.D., and
Marie Nordsieck, B.A.
Heart Direase Control Program, Public Health Service
ADDRESS: (C.J.M.) Director of Crippled Children’s Service and Professor of Preventive Medicine,
School of Medicine, University of Missouri, Columbia, Missouri.
42
PEDIATRICS, July 1962
A
GREAT DEAL of spirit is usuallygen-erated in any discussion of the “func-tional” or “innocent” murmur in children.
The
innocence
of these
systolic
vibrations
is supported and denied with equal vigor
and
emotion.
These
divergent
views
are
usually identified on the one hand with the pediatrician convinced of their innocence and conversely with the internist who is more apt to equate the murmur with or-ganic ty2 This disagreement ap-pears to be a natural sequence of the fact that the physician dealing entirely with children hears these murmurs in well over 50% of his patients; on the other hand, a murmur is more unusual and generally con-sidered significant of some underlying pa-thology when distinctly and loudly heard in the adult.
Description leaves much to be desired in the longitudinal evaluation of the persist-ence or disappearance of murmurs heard in childhood, since rarely is the same physi-cian fortunate enough to follow his patients over a prolonged period. Should he have this opportunity, his impressions of auscul-tatory findings would change over the years as new information becomes available or his experience enlarges. A systolic murmur described in detail 20 years ago may call for a much different word picture today.
Comparison of two photographic record-ings of the patient’s heart sounds-one taken during school age and the other in adulthood-so that both could be inter-preted in the light of present day knowl-edge, might aid in deciding questions of innocence and persistence of the murmurs. The presence or absence of organic abnor-malities in other cardiovascular parameters would indicate that 20 or more years of ac-tive adolescence and young adult life as a
“physiologic test” had either absolved or incriminated the murmur recorded in child-hood.
An opportunity to do a pilot study of this type developed during an investigation on obesity in children as related to overweight in adults in the community of Hagerstown, Maryland. It was discovered the 1,482 chil-dren had participated in a study of phono-cardiograms in 1939. These phonocardio-graphic records and the machine used were made available to us. One of the authors (Boone) of the previous study3 was kind enough to describe and document the quantitative equality of the stethographic and stethoscopic examinations done at that time.
It was decided to obtain repeat phono-cardiograms, electrocardiograms, histories, and physical findings, of now adult individ-uals who had previously had “innocuous” murmurs. The childhood murmurs would then have been truly innocent only if there were no evidence of the development of heart disease beyond that expected among normal individuals during this intervening 20-year period; and organic or pathologic if most or all had evidence of now diag-nosable “heart disease.”
REVIEW OF THE LITERATURE
iNTENSITY GRADES OF
SYSTOUC VIBRATIONS
SCHEMATIC ACTUAL
__J::ir
-
.
PERCEPTIBLE SV
DEFINITE
MARKED
ARTICLES 43
The estimation of prognosis of apical systolic murmurs in the past has usually in-cluded all types, whether “functional” or organic. The following mortality ratios com-pared to standard ordinary life insurance risk (as 100%) were reported by the Metro-politan Life Insurance Company5: (1) an inconstant apical murmur-111%, (2) a con-stant murmur with no transmission-137%, and
(
3) a constant murmur with transmis-sion-214%. All of these had no cardiac en-largement at the time of the examination.Steuer and Fineberg,6 in 1938, found that 30% of 100 children with apical murmurs developed organic heart disease after 6 years of observation.
These studies indicate a degree of seri-ousness certainly not to be expected if the murmurs were truly innocuous. Clearly, many, if not the majority, of these murmurs must have been of definite rheumatic mitral insufficiency, now usually rather easily sep-arable from the vibratory “functional” mur-mur.
As recently as 1948, Epstein7 found that more than 50% of his patients had systolic murmurs during the first 14 years of life, but he stated that “contrary to the reports of some observers, the character, location and transmission of murmurs heard in over half of the group were indistinguishable from those of the murmur of mitral insuf-ficiency.”
Messeloff,8 in 1949, analyzed a series of 300 children with “functional murmurs”; he concluded that no pathognomonic fea-tures could distinguish functional from or-ganic murmurs. His measures of the “truly distinctive” features of organic heart dis-ease were, however, the electrocardiogram and x-ray, which in children involves a greater margin of error than the stetho-scope.
Harris et al.,#{176}using the phonocardiogram, studied the wave form differentiation be-tween the apical blowing systolic murmur of mitral insufficiency and that of the vi-bratory “innocent” murmur heard just in-side the apex. The innocent murmur on phonocardiographic tracing was described as being of regular frequency, vibratory,
-(
Fic. 1. Schematic representation of the threefold
classification of systolic vibrations according to
grade of intensity and examples from actual
stethographic records. SV indicates systolic
vibra-lions. (Reproduced, with permission, from Boone
and Ciocco,’ Milbank Mem. Fund Quart., 17: no.
4, 1939.)
and having a sine wave curve resembling that of a pure tone without overtones.
The
vibratory murmur did not begin immedi-ately after the first tone, as did the murmur of mitral insufficiency. The vibratory mur-mur also did not extend beyond the second third of the systolic interval and
had
its
maximal intensity at mid-point. The average duration of the murmur was 0.114 second as compared to the 0.24 second average duration of the blowing murmur of mitral in-sufficiency. The intensity of the “innocent” murmur was frequently as great or greater than that of the mitral murmur. This de-scription has not changed remarkably since that time.10’1’
Rushmer
et al.,12in
1953,demonstrated
ob-TIl1IUStfr1
S S S S S S
i1’
FIG. 2. Examples, showing functional murmurs, selected from phonocardiograms
Hagerstown, Maryland.
T1J# LII
iii.
___
taken in 1939 in
servers. He made the classic observation in justifying the use of the murmur alone in defining its innocent nature by stating that its acoustical quality may be likened to the familiar voice on the telephone which is easily distinguished by the ear even though its phonographic tracing may not be dis-tinctive.
Rhodes, in 1955, stated that the inno-cent murmur is often louder than that of mitral insufficiency and that the effect of exercise is variable. Fogel,’4 in 1957, felt
strongly that the characteristics of the vi-bratory parasternal precordial murmur were sufficiently definite, so that in the absence of a positive clinical history and with a nor-mal cardiac size and contour and a normal electrocardiogram, the child may be dis-charged from further cardiac follow-up.
spectro-ARTICLES
45graph,16 he increased the range of fre-quencies to 125 to 240 cycles per second in comparison to 850 to 1,220 cycles per see-ond in the case of mitral insufficiency, or well over 750 cycles per second for con-genital cardiac defects.
Paulin and Mannheimer2 described as “physiologic” the diamond-shaped vibra-tory murmur over the precordium which is either unchanged or slightly louder after increasing the cardiac output. In their in-troductory remarks they sound the clear warning in regard to the unnecessary in-validization of children on the basis of these murmurs.
The examiner who is not acquainted with the findings on auscultation of the heart in children, will be surprised as to the wealth of findings. The ability “to hear better,” introduces the great danger
of overestimating the auscultatory findings.
In reviewing the divergent opinions in regard to the innocent, innocuous, or func-tional nature of these murmurs, one can but wonder whether the ghost of the innocent murmur, editorially “laid to rest” some years ago,1 does not still stalk our land.
METHOD
Approximately 3,000 phonocardiographic
records taken in 1939 upon a group of 1,460
children in three schools in Hagerstown, Maryland, were re-examined and inter-preted by the authors.
Boone and Ciocco,3 in their original re-ports, had classified the murmurs (systolic vibrations) as perceptible, 36%; definite 20%; and marked, 3%. The agreement of the read-ings separated by the 20-year span of time was excellent.
One of the authors (B.B.) in a personal communication had informed us that all systolic vibrations in the definite and marked category, in the 1939 study, had been definitely and equally audible upon stethoscopic examination. We are therefore considering the definite systolic vibration
seen on phonocardiogram to be equivalent to grade II or more vibratory murmur
heard in 1939. This has also been borne out
in
the
comparison
of
the
re-examination
auscultation and the phonocardiographic recording.
The first step then was to eliminate those recordings in which there could have been any question of auscultatory inaudibility, and to select only those in which the mur-murs were classed as definite or marked.
Criteria for the selection of the innocent murmur, based upon the work of Harris and 15 were as follows:
Maximal duration: 0.09 ± 0.02 second,
which constitutes one-half of the mean du-ration of the systolic interval as determined by Boone and Ciocco17 on this group of
children in 1939. Frequency: The range chosen was 80-180 cycles per second as determined by Harris. Timing: A definite interval between the murmur and
the first
and second heart sound. Quality:
Constant,
single-tone vibration with a slight waxing and waning diamond-like shape on stetho-gram. Intensity: Using
the heart
tones
and
width of base line as comparison points, only those classed as “definite” and “marked” as illustrated by Boone and Ciocco were chosen.
The
phonocardiograms
of
154 children were acceptable as showing a definite or marked systolic vibratory murmur. By a thorough search, 139 of these now adult in-dividuals were located (90% of the total selected); 96 were chosen forre-examina-tion because they lived
in the
local
area,
and all agreed to a repeat examination by one or several of the authors. The examina-tion consisted of a complete cardiovascular history, utilizing the “Framingham” study
forms; physical examination; chest film; 15-lead electrocardiogram; and
phonocardio-gram.
These records and the auscultatory find-ings were described and subsequently com-pared with the original phonocardiographic records. A group of 4-lead electrocardio-grams and roentgenograms had been taken in 1939 and were also interpreted when available.
per-TABLE I
OUTCOME, IN 1960, OF 96 CHILDHOOD VIBRATORY
MURMURS OBSERVED IN 1939
Murmurs
Per-sons (no.)
Heart Disease in 1960
vot
Preseni Presenl Type
Old murmur 18 17 1 Anemia with left
retained ventricular
by-pertrophy
Old murmur 77 75 Hypertension with
disappeared left ventricular
hypert.rophy, no murmur (1st
case)
Left bundle branch block, no mur-mur; former “paratrooper” (end case) New murmur 1 0 1 Left ventricular
present* hypertrophy;
in-tercurrent rheu-matic fever with rheumatic mi-tral insuffi-ciency; no defi-nite rheumatic history
Total 96 9 4
* Organic murmur unrelated to original vibratory murmur.
centage of the total group examined in whom the vibratory murmur was retained or had disappeared after the 20-year in-terval and (2) the relationship of the pres-ence or absence of current heart disease to the childhood murmur heard (Table I).
COMMENT
In this group of 96 persons with vibra-tory murmurs in childhood, only four cases of heart disease were found, and only two of these could be even remotely related to the previous murmur. The absence of heart disease in the majority would appear to in-dicate that the vibratory systolic murmurs recorded and heard in childhood, even though quite loud, were innocuous or in-nocent and not indicative of organic heart disease. The 20 years of elapsed time, with
its coincident adolescent and young adult physical activity, should have given evi-dence of cardiac strain and hypertrophy had these original murmurs been “organic” or significant of underlying heart disease.
There
are little data on the expected cardiovascular morbidity in this age group over a 20-year period. Prevalence estimates of 2% have been made (White18). This figure would be in agreement with our findings and would class the entire group of 96 as having been “normar at the time of their original examination. We are aware that there is a definite element of selection op-erating against the consideration of this study as a statistically valid proof of the innocence of the original murmur. Selection is inherent because only those persons who are available in the area could be re-examined. However, in addition to the 96 examined, we have determined that 32 others are in good health but inaccessible by virtue of distance; 1 had been killed while serving with the Armed Forces. The death certificates for the State of Maryland have been checked for all names on the missing list. There are then 14 remaining who have not been located. In order to as-sume that the original murmurs were or-ganic, it would be necessary to make an additional and implausible assumption that every one of the missing individuals hasheart disease or has died of this disease. This assumption would still not bring the percentage of heart disease to the range necessary to compare with the 20-year rheumatic heart disease studies of Ash’#{176} or Bland and Jones,2#{176}in which 91% and 93%, respectively showed continuing heart dis-ease. Of Steuer’s children’s heart clinic pop-ulation, 27% developed serious heart dis-ease and 61% of them still had systolic mur-murs after 10 years. The burden of proof, it
would seem, would thus rest with those
who
would
class
the
original
murmurs
as
organic by virtue of the selection of the examined population.
In view of the small numbers involved in this study, no claim of “proof of innocence”
ARTICLES 47
the longitudinal testing of the significance of vibratory systolic murmurs is feasible. An answer could be obtained by the re-examination of large numbers of children who have had phonocardiographic exami-nations.
Boone and Ciocco in their work 20 years ago stated in their conclusion that “it is generally assumed that in childhood the variations from the basic (normal) pattern are the expressions of physiologic states peculiar to this age period. The important question arises as to whether the manifesta-tion of variations in childhood is associated with the acquisition of heart disease in later life. It is hoped that through the repeated examination of these children and through the intensive study of children and adults with heart disease, a definite contribution will be made toward answering this impor-tant question.”
Their conclusion serves both as a justifi-cation for this limited study and as a frame-work upon which to express our own hope that more and better data will accumulate to aid in the elimination of the still too-prevalent iatrogenic heart disease diagnosis induced by the presence of these murmurs in children.
We would tend to agree with Fogel’s14
suggestion
that
the
murmur
itself
canbe
identified and may be excluded from con-sideration as “disease” by direct or primary action and not necessarily by a process of elimination requiring, in each instance, an entire battery of physiologic tests.
The following statement of Still,4 made in 1918, cannot be improved:
Whatever may be its origin, I think it is clearly functional, that is to say, not due to any organic disease of the heart either congenital or ac-quired; and I mention it in connexion with
endo-carditis because I have seen several cases inwhich it has given rise not only to groundless alarm,
but to unnecessary restrictions, so that the child
has been treated as an invalid and not allowed to
walk about.
SUMMARY
One hundred
fifty-four
phonocardiograms
showing
vibratory
“innocuous”
systolic
mur-murs were chosen from a group taken in 1939. Of the patients, 139 now adults were located; 96 were re-examined by history, physical examination, roentgenograms, elec-trocardiograms, and a repeated phonocardi-ogram.
Two
of this
group
had
heart
dis-ease, presumably related to the childhood murmur.
Two
individuals
had
heart
dis-ease not related to the previous murmurs. Despite the fact that not all 154 could be located, the low 20-year incidence of heart disease and the complete disappearance of the murmur in 80% of those examined ap-pear to indicate the great likelihood that the childhood vibratory, low-frequency, mid-systolic apical and precordial murmur is indeed innocuous and should not be taken as evidence of heart disease unless
there
is other
evidence.
REFERENCES
1. Luisada, A. : The “functional” murmur: the laying to rest of a ghost. Dis. Chest, 27: 579, 1955.
2. Paulin, S., and Mannheiiner, B. : The physio-logical heart murmur in children. Acta
Paediat. (Upps.), 46:438, 1957.
3. Boone, B. R., and Ciocco, A. : Cardiometric studies on children: I. Stethographic pat-terns of heart sounds observed in 1,482
children. Milbank Mem. Fund Quart., 17: no. 4, 1939.
4. Still, C. H. : Common disorders and diseases
of childhood, Ed. 3. London, Oxford
Uni-versity Press, 1918, page 495.
5. Metropolitan Life Insurance Co.: Prognosis in
Heart Disease. Based upon impairment study made by Society of Actuaries 1951. Modern Medicine, 22:101, 1954.
6. Steuer, G., and Fineberg, M. H.: Further
ob-servations on apical systolic murmurs in children. Amer. Heart J., 16:351, 1938. 7. Epstein, N.: The heart in normal infants and
children: incidence of precordial systolic
murmurs and fluoroscopic and electrocardi-ographic studies. J. Pediat., 32:39, 1948.
8. Messeloff, C. R.: Functional systolic murmurs in children. Amer.
J.
Med. Sci., 217:71, 1949.9. Harris, T. N., Friedman, S., and Haub, C. F.: Phonocardiographic differentiation of the
murmur of mitral insufficiency from some commonly heard adventitious sounds in childhood. PEDI.&Tlucs, 3:845-853, 1949.
In-nocent (functional) murmur. Heart Bull., 9: 93, 1960.
11. Hardman, V., and Butterworth, J. S.: Auscul-tation of the heart: Part II. Mod. Conc. Cardiov. Dis., 30:651, 1961.
12. Rushmer, R. F., et al.: Variability in detec-tion and interpretation of heart murmurs: a comparison of auscultation and stethog-raphy. Amer. J. Dis. Child., 83:740, 1952.
13. Rhodes, P.: The diagnosis of innocent heart murmur in children. Bull. Denver Rheum. Fever Diagnostic Service, 1:1, 1955. 14. Fogel, D. H.: The innocent (functional)
car-diac murmur in children. PEDIATRICs, 19: 793, 1957.
15. Harris, T. N., and Needleman, H. L.: Study
by cathode-ray oscillography of some
in-nocent and pathologic cardiac murmurs of
children. Amer. Heart J., 52:887, 1956. 16. Harris, T. N., et al.: Spectrographic
compari-son of ranges of vibration frequency among some innocent cardiac murmurs in child. hood and some murmurs of valvular insuffi-ciency. PEDIATRICS, 19:57, 1957.
17. Boone, B. R., and Ciocco, A.: Cardiometric
studies on children: II. The duration of the component parts of the cardiac sound cycle. Milbank Mem. Fund. Quart., 18:137,
1940.
18. White, P. D.: Heart Disease, Ed. 3. New York, McMillan, 1944, p. 250.
19. Ash, R.: The first ten years of rheumatic in-fection in childhood. Amer. Heart J., 36: 89, 1948.
20. Bland, E. F., and Jones, T. D.: Rheumatic fever and rheumatic heart disease: a 20-year report on 1,000 patients followed since childhood. Circulation, 4:836, 1951.
Acknowledgment
We wish to express our sincere appreciation to Dr. William Cameron, Deputy State Health Officer, Washington County, Maryland, and his staff and the Community Health Studies staff of the Divi-sion of Public Health Methods, Public Health
Service, in Hagerstown, Maryland, for their
in-valuable help and co-operation which made this
