Pediatric Murmurs

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Pediatric Murmurs

• When should we worry?

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For a link to sound files demonstrating examples
of the heart sounds and murmurs in this
presentation go to www.cardiologysite.com and
select cardiac auscultation from the pull down
topics in the upper left corner.
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General Information

• Murmurs are audible turbulent sound waves in the
  range of 20 to 2000 Hz produced by the heart and
  vascular system.
• Cardiac murmurs are a common finding in children
  and represent the most frequent reason for
  referral to a cardiologist.
• The majority of murmurs are normal occurring in
  almost 50 of all school aged children, but need
  to be distinguished from pathologic ones.
• Auscultation in the context of a careful history
  and appropriate physical exam can help guide the
  pediatrician toward an accurate diagnosis.

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Timing of Presentation

• The patients age at recognition may dictate the
  nature of the anomaly and the urgency for
  evaluation.
• The majority of significant structural congenital
  heart disease is recognized in the first few
  weeks of life.

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Timing contd

• Ductal-dependent abnormalities, such as pulmonary
  atresia, transposition of the great arteries,
  coarctation of the aorta, hypoplastic left heart,
  or significant outflow obstructions such as
  aortic valve stenosis, present in the first few
  days of life.
• In the absence of an associated anomaly,
  hemodynamically significant VSDs rarely present
  before 2 weeks of age, and ASDs are rarely
  symptomatic in infancy.

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History

• Assessment should include inquiries about family
  history, pregnancy, perinatal course, and
  symptoms of cardiovascular disease in the
  patient.
• Structural heart disease is often seen in
  association with certain recognizable syndromes
  (Table 1).
• A family history of sudden death, rheumatic
  fever, SIDS, or a structural cardiac abnormality
  in a first degree relative may be significant.

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History contd

• A maternal history for GDM may be associated with
  transient hypertrophic cardiomyopathy in addition
  to ASDs and aortic coarctation in as many as 30
  of infants.
• Other relevant pregnancy history may include the
  presence of acute/chronic maternal illness,
  congenital infections (rubella, CMV, herpes,
  coxsackie), and drug use, which may be associated
  with structural heart disease.

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Symptoms

• In infants, feeding problems are often the first
  indication of CHF, which occurs in about 30 of
  infants and children with congenital heart
  disease.
• May be evidenced by disinterest, excessive
  fatigue, diaphoresis, change in respiratory
  pattern, tachypnea, or dyspnea.
• A quantitative measure of feeding volume is
  helpful.

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Symptoms contd

• An age relevant index of exertional tolerance
  should be sought in all children as an indication
  of cardiovascular fitness and functional
  capability.
• In older children chest pain (especially with
  exertion), and syncope need to be investigated.
• A history of cardiac/exercise induced asthma and
  frequent respiratory tract infections may
  indicate abnormalities of pulmonary blood flow
  and airway compression secondary to plethoric
  vessels.

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Symptoms contd

• Cyanosis is evident in one third of infants with
  potentially lethal congenital heart disease.
• Central cyanosis differs from acrocyanosis by
  involvement of the warm mucous membranes (i.e.
  tongue and buccal mucosa).
• Acrocyanosis is generally confined to the
  perioral, perinasal skin and nail beds.
• Central cyanosis generally worsens with activity
  and increasing cardiac output while acrocyanosis
  generally improves with activity.

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Physical Examination

• Vital signs and appearance
• Height and weight should be obtained and plotted
  on a growth chart.
• Respiratory Assessment
• Respiratory rates should be assessed in quiet,
  fasting infants for a full minute as patterns can
  vary considerably with activity and feeding.
• In addition to noting the rate, depth, and effort
  of respiration, inspection should include
  observation for evidence of air trapping, and
  increased chest diameter.

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Physical Examination contd

• Blood Pressure
• Proper technique and equipment needs to be used.
  Automated devices are acceptable in newborns and
  infants.
• Every child should have a comparison of bilateral
  upper and lower extremity blood pressures on at
  least one occasion. Due to artifact the lower
  limb blood pressure is normally 10 mm Hg higher
  than the upper limb pressure.
• Appearance
• Sick infants often appear anxious, diaphoretic,
  pale, or breathless and are seldom consolable.
• Evidence of cyanosis, pallor, clubbing, and
  possible dysmorphic features that suggest
  specific structural cardiac anomalies should be
  looked for.

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Physical Examination contd

• Arterial Examination
• Pulses should be assessed for rate, rhythm,
  volume and character. A clinical index of
  cardiac output includes the warmth of the digits
  and capillary refill.
• Initially, the radial and brachial pulses should
  be assessed simultaneously to afford a more
  accurate assessment of the rate of arterial
  pressure rise, volume and contour.
• Assessment of the femoral pulse requires the
  infant to be quiet/happy. Presence of a palpable
  femoral pulse is an inadequate screen for
  coarctation given evolution of collateral flow
• The radial pulse should be brought in close
  apposition to the femoral pulse to compare for
  any temporal delay, a manifestation of aortic
  coarctation.

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Physical Examination contd

• Venous/Abdominal Examination
• Jugular venous pulse is difficult to assess in
  infants and children. Therefore the liver
  character and size offer a more reliable
  indicator of systemic congestion.
• Assess the position, size and consistency of the
  liver. In newborns the liver may be palpable
  normally at 2.5 cm to 3 cm below the right costal
  margin in the mid-clavicular line. This
  decreases to about 1cm to 2 cm by 1 year and
  remains just palpable to school age.

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Physical Examination contd

• In the presence of CHF the liver enlarges and
  distends downward. The congested liver margin
  becomes rounded and firm and may be more
  difficult to feel.
• The enlarged spleen should always be sought and
  suggests endocarditis in patients with heart
  murmurs. Splenic enlargement in association with
  CHF is unusual.

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Physical Examination contd

• Cardiac Exam
• Precordial Examination
• Fully apply the entire palm of the hand to the
  chest wall to maximize the ability to detect
  thrills or heaves.
• Use the fingertips to localize the apical impulse
  which should be confined to one intercostal
  interspace.
• Thrills should be sought in the precordial and
  suprasternal areas utilizing the palmar surface
  of the metacarpals and first phalanges.

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Physical Examination contd

• Auscultation
• Should be performed under optimal conditions in
  the supine, sitting and standing positions.
• Listen systematically to all aspects of the
  cardiac cycle and all auscultatory areas with
  both the bell and diaphragm.
• S1 arises from closure of the atrioventricular
  (mitral/tricuspid) valves in early isovolumic
  ventricular contraction. Mitral valve closure
  occurs slightly in advance of tricuspid valve
  closure, and occasionally normal splitting can be
  heard. Normally it is heard as a single sound.
  It is more easily heard when the heart rate is
  slower because the interval between S1 and S2 is
  shorter than between S2 and S1.

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Physical Examination contd

• S2 is generated by closure of the semilunar
  valves (aortic/pulmonic). Normally comprised of
  a louder/earlier aortic component and
  quieter/later pulmonic component. Due to
  physiologic variations during inspiration, the
  split becomes more pronounced.
• S3 is a third heart sound which can be a normal
  finding in about 6-10 of children and young
  adults. It is caused by sudden limitation of
  longitudinal expansion of the ventricular wall.
  It is a brief low pitched sound in mid-diastole
  best heard with the bell of the stethescope and
  child on their left side.
• S4 is the presystolic gallop. It is produced by
  vibrations in expanding ventricles during rapid
  diastolic filling as the atria contract and
  reflect myocardial stiffness. It occurs late in
  diastole and is of low pitch and intensity.

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Classification of Murmurs

• Timing
• The relative position within the cardiac cycle
  and relation to S1/S2.
• Intensity
• Grade 1 Heard only with intense concentration
• Grade 2 Faint, but heard immediately
• Grade 3 Easily heard, of intermediate intensity
• Grade 4 Easily heard and associated with a
  thrill
• Grade 5 Very loud, with thrill and audible with
  only edge of stethoscope on chest wall
• Grade 6 Audible with stethoscope off the chest
  wall

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Classification of Murmurs cont'

• Location on the chest wall with regard to
• The area of maximal intensity
• The extent of radiation
• Duration
• The length of time of the murmur
• Configuration
• The dynamic shape of the murmur
• Pitch
• The frequency range of the murmur
• Quality
• The presence of harmonics and overtones

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Classification of Murmurs contd

• Systolic Murmurs
• Holosystolic- Abruptly begin with S1 and
  continues with the same intensity to S2. Occurs
  with regurgutant AV valves or in association with
  the majority of VSDs.
• Ejection- Crescendo-decrescendo in configuration
  reflecting the periods of low flow at the
  beginning and end of systole. Innocent murmurs
  are almost exclusively described in this way.
• Early systolic- Abruptly begin with S1, but taper
  and disappear before S2. Associated with small
  muscular VSDs.
• Mid to late systolic- Begins midway through
  systole and often associated with the midsystolic
  clicks/insufficiency of MVP.

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Classification of Murmurs contd

• Diastolic Murmurs
• Early diastolic- Decrescendo in nature and arise
  from aortic/pulmonary regurgitation.
• Mid diastolic- Occur because of either increased
  flow across a normal AV valve or normal flow
  across an obstructed or stenotic valve.
• Late diastolic- Created by stenotic or narrowed
  AV valves in association with atrial contraction.
• Continuous Murmurs
• Occur as a result of flow through vessels distal
  to the aortic/pulmonary valves and therefore not
  confined to systole and diastole.
• May be heard through part or all of diastole.
• Generally pathologic with the venous hum being an
  exception.

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Innocent Murmurs

• Vibratory Stills Murmur
• Most typically audible between ages 2 and 6
  years, but may be present as late as adolescence
  and as early as infancy.
• Low to medium in pitch, confined to early
  systole, grade 1-3, and maximal at the LLSB
  extending to the apex.
• Loudest while in the supine position, and
  described as vibratory or musical in quality.
• Origin is uncertain, but possibly related to the
  presence of ventricular false tendons.

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Innocent Murmurs contd

• Pulmonary Flow Murmur
• An outflow tract murmur that may be heard in
  children, adolescents, and young adults.
• A crescendo-decrescendo systolic ejection murmur
  confined to the second and third interspace of
  the LSB.
• Usually of low intensity (grade 2-3), transmits
  to the pulmonary area and is best heard when pt
  is supine.
• Described as rough and dissonant without a
  Stills vibratory quality.
• May be difficult to distinguish from an ASD or PV
  stenosis but the lack of fixed, widely split S2,
  mid diastolic flow rumble, thrill or ejection
  click should facilitate distinction.

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Innocent Murmurs contd

• Peripheral Pulmonary Arterial Stenosis Murmur
• Heard frequently in normal newborns and infants
  less than 1 year of age, but may be associated
  with respiratory tract infections and RAD in
  older infants.
• It is the audible turbulence of peripheral branch
  pulmonary arterial stenosis, angulation or
  narrowing.
• Ejection murmurs typically graded 1 to 2, low to
  moderate pitch, beginning in early to mid
  systole, and extending up to and occasionally
  beyond S2.

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Innocent Murmurs contd

• Often heard best peripherally in the axillae and
  back, with both regional and temporal
  variability.
• Intensity may change with heart rate variability,
  increasing with slow HR (increased SV), and
  diminishing with tachycardia (reduced SV).
• May be indistinguishable from pathologic stenosis
  as seen in Williams or rubella syndromes or with
  hypoplastic pulmonary arteries. Murmurs of
  significant stenosis are often higher in pitch,
  extend beyond S2, and occur in children beyond
  the first few months of life.

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Innocent Murmurs contd

• Supraclavicular/Brachiocephalic Systolic Murmur
• A crescendo-decrescendo murmur that is heard in
  children and young adults.
• Audible maximally above the clavicles and
  radiates to the neck. May be present to a lesser
  degree on the superior chest.
• Low to medium in pitch, abrupt in onset, brief,
  and maximal in the first half to two thirds of
  systole.
• The murmur is present with the patient both
  supine and sitting but diminishes with
  hyperextension of the shoulders.
• Thought to arise from the brachiocephalic vessels
  as they arise from the aorta.

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Innocent Murmurs contd

• Aortic Systolic Murmur
• Arise from the aortic outflow tract in older
  children and adults.
• Ejection in character, confined to systole, and
  loudest over the aortic area.
• In children may develop secondarily to anxiety,
  anemia, hyperthyroidism, fever or other
  conditions causing increased cardiac output.
• Needs to be distinguished from IHSS and other
  obstructions of LV outflow tract. Referral or
  further investigations are often warranted.

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Innocent Murmurs contd

• Venous Hum
• The most common type of continuous murmur heard
  in children.
• Most audible on the low anterior portion of the
  neck just lateral to the SCM, and is a caused by
  the flow of venous blood from the head/neck into
  the thorax.
• Generally louder on the right, and with the
  patient sitting. Intensity varies from faint to
  a grade 6. Variable in character, often
  described as whining, roaring, or whirring.
• Often resolves or changes in character with lying
  down, and may be eliminated with gentle
  compression of the jugular vein or the pt turning
  their head to the side of the murmur.
• All other diastolic murmurs are pathologic and
  justify referral.

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Innocent Murmurs contd

• Mammary Arterial Souffle
• Occurs most commonly late in pregnancy and in
  lactating women, but rarely in adolescence.
• Arises in systole but may extend well into
  diastole, being maximally audible on the anterior
  chest wall over the breast.
• Generally high pitched with highly variable
  character.
• Thought to be arterial in origin, arising from
  the plethoric vessels of the chest wall.
  Resolves with termination of lactation.

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Pathologic Murmurs

• Atrial Septal Defect
• Findings can be quite subtle and confused with
  those of innocent murmurs.
• May demonstrate increased precordial activity
  secondary to right ventricular enlargement.
• The murmur is often of low pitch and intensity.
  It is a result of increased blood volume across
  the right ventricular outflow tract. Usually
  loudest at the LUSB. There may also be a
  diastolic murmur or rumble due to increased flow
  across the tricuspid valve. Often best heard
  with the bell along the LLSB. Demonstrates no
  change with position. S2 is often widely split
  and fixed.

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Pathologic Murmurs contd

• Pulmonary Stenosis
• An ejection murmur at the LUSB associated with a
  thrill and ejection click.
• Inspiration intensifies the murmur and expiration
  intensifies the click.
• Idiopathic Hypertrophic Subaortic Stenosis
• A harsh ejection murmur loudest near the apex.
• Murmur is intensified by standing after
  squatting, and the Valsalva maneuver.
• Given the high incidence of inheritance (gt20) a
  family history of an affected first degree
  relative arguably justifies an ECHO.

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Pathologic Murmurs contd

• Patent Ductus Arteriosus
• A congenital lesion often detected at birth,
  especially in preterm infants.
• A continuous murmur along the LUSB (seldom
  continuous in neonates). Grade 1-4, machinery
  like in quality and possibly associated with a
  thrill.
• Associated signs are bounding pulses, precordial
  hyperactivity and intensification with supination.

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Summary

• Effective cardiac murmur evaluation relies on
  obtaining an appropriate history as well as
  physician comfort and proficiency with
  auscultation.
• Index for concern should be based on the
  patients age, significant history, and cardiac
  findings.
• The clinical diagnosis of an innocent or normal
  murmur should only occur in the setting of an
  otherwise normal history, exam and appearance.

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Summary contd

• Innocent murmurs are never solely diastolic and
  typically grade 3 or less.
• Referral to cardiology is appropriate any time
  there is doubt or concern.
• It is important to reassure the patient and their
  family after a diagnosis of innocent murmur is
  made so as to limit unresolved anxiety and
  inappropriate activity restriction or medication
  use.

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References

• Pelech, Andrew N Evaluation of the Pediatric
  Patient with a Cardiac Murmur. Pediatric Clinics
  of North America 46167-188, 1999.
• Pelech, Andrew N The Cardiac Murmur When to
  Refer? Pediatric Clinics of North America
  45107-122, 1998.
• Allen HD, Golinko RJ, Williams RG Heart Murmurs
  In Children When is a Workup Needed?
  Contemporary Pediatrics 1129-52, 1994.
• McConnell ME, Adkins SB, Hannon DW Heart Murmurs
  in Pediatric Patients When Do You Refer?
  American Family Physician 60558-564, 1999.