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Heart Murmurs
Ninety percent of children will have an audible heart murmur at some point in time. Normal murmurs include vibratory and pulmonary flow murmurs, venous hums, carotid bruits, and the murmur of physiologic branch pulmonary artery stenosis. Less than 5% of heart murmurs in children are caused by cardiac pathology, such as mitral regurgitation and reflux.
Clinical Evaluation of Heart Murmurs
Cyanosis, exercise intolerance, feeding difficulties, dyspnea, or syncope signify potential cardiac dysfunction. Failure to thrive, diffuse diaphoresis, unexplained persistent irritability or lethargy, and atypical chest pain also suggest the possibility.
The majority of children who have heart murmurs are asymptomatic. In early infancy, however, cardiac malformations that are critical may manifest as persistent peaceful tachypnea.
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Syndromes and Associated Cardiac Malformations
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Syndrome
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Incidence of Cardiac Malformations (%)
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Cardiac Malformations
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Down Syndrome
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50
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AVSD, VSD, ASD, PDA, TOF
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Trisomy 18
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99
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VSD, PDA, DORV, BPV
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Trisomy 13
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90
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VSD, ASD, PDA
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Turner Syndrome
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40
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Aortic coarctation, AVS, HLH
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Noonan Syndrome
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50
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PVS, HCM
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William Syndrome
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90
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SVAS, SVPS, RAS
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Marfan Syndrome
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60-80
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MVP, AoRD, AI
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DiGeorge Syndrome
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90
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IAA (B), TA
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VACTERL
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80
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VSD, ASD, PDA, TOF
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AVSD = atrioventricular septal or canal defect, VSD = ventricular septal defect, ASD = atrial septal defect, PDA = patent ductus arteriosus, TOF = tetralogy of Fallot, DORV = double outlet right ventricle, BPV = bicuspid pulmonary valve, AVS = aortic valve stenosis, HLH = hypoplastic left heart, PVS = pulmonary valve stenosis, HCM = hypertrophic cardiomyopathy, SVAS = supravalvular aortic stenosis, SVPS = supravalvular pulmonary stenosis, RAS = renal artery stenosis, MVP = mitral valve prolapse, AoRD = aortic root dilatation, AI = aortic insufficiency, IAA (B) = interrupted
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Family history of a congenital cardiovascular malformation increases the risk of a cardiac defect.
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Characteristics of Organic Murmurs
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Lesion
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Shape
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Timing
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Location
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Other Findings
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Ventricular septal defect (VSD)
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Plateau
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Holosystolic
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LLSB
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Apical mid- diastolic murmur
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Mitral regurgitation
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Plateau
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Holosystolic
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Apex
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Higher pitched than VSD murmur
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Atrial septal defect
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Ejection
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Systolic
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ULSB
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Persistent S2 split
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Patent ductus arteriosus
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Diamond
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Continuous
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ULSB
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Bounding pulses
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Aortic valve stenosis
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Ejection
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Systolic
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URSB
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Ejection click
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Subvalvular aortic stenosis
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Ejection
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Systolic
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ML-URSB
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No ejection click
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Hypertrophic cardiomyopathy
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Ejection
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Systolic
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LLSB- apex
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Laterally displaced PMI
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Coarctation
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Ejection
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Systolic
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ULSB-Left back
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Pulse disparity
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Pulmonary valve stenosis
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Ejection
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Systolic
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ULSB
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Ejection click; wide S2 split
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Tetralogy of Fallot
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Ejection
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Systolic
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MLSB
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Cyanosis
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LLSB = lower left sternal border, ULSB = upper left sternal border, URSB = upper right sternal border, MLSB = mid-left sternal border, S2 = second heart sound, PMI = point of maximal impulse.
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Ventricular septal defect (VSD) is a harsh pansystolic murmur of even amplitude that is audible at the lower left sternal border.
Patent ductus arteriosus (PDA) causes a murmur that is continuous, louder in systole, and located at the upper left sternal border.
Ejection (crescendo-decrescendo) murmurs are caused by ventricular outflow obstruction. Ejection murmurs begin after the first heart sound.
Treatment of Heart Murmurs in the Newborn Infant
Sixty percent of healthy term newborn infants have normal heart murmurs. One third of neonates who have
Thirty percent of newborn infants subsequently determined to have heart disease are discharged from the
Persistent peaceful tachypnea should not be dismissed; 90% of infants who have serious cardiac disease have persistent tachypnea after birth.
A persistently hyperdynamic precordium suggests
Auscultation of the Second Heart Sound. In healthy neonates, the second heart sound is split audibly by 12 hours of age. In general, a split second heart sound signifies the normal presence of
Neonates who have critical heart disease almost always have an audibly single and often accentuated
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