Cardiac Murmurs in the
Newborn Infant
Carrie Phillipi MD, PhD
Prevalence of Congenital Heart
Disease (CHD)
• <1 per 100 live births
Most cardiac murmurs are benign!
Risk Factors for CHD
(when is CHD more likely)
• Family history of CHD
• Increased maternal age: increased risk for
chromosomal abnormalities
• Genetic syndromes (Down syndrome, Turner’s)
• Finding of other major anomalies (VATER, cleft
palate, neural tube, etc.)
• Plurality (multiple gestation)
Maternal Risk Factors for CHD
• Maternal Diabetes: 3-5% risk of CHD
– VSD, conotruncal defects, d-TGA
– Risk reduced with good diabetic control
– Importance of supplemental vitamins
(Folate)
• Maternal systemic lupus
– Complete heart block
– Transplancental passage of maternal antiSS-A or anti-SS-B autoantibodies
Genetic Risk for CHD
• Chromosome Disorders
– Trisomy 21 (Down Syndrome)
• ~50% have CHD
• AVSD, VSD, PDA, ASD
– Trisomy 18 and 13
• >90% have CHD
• VSD, DORV, PDA, conotruncal defects
Genetic Risk for CHD
• Chromosome Disorders
– 45X deletion syndrome (Turner syndrome):
35% have CHD: coarctation, bicuspid aortic
valve, potential for developing aneurysm of
aorta
– 22q11 deletion (DiGeorge syndrome; Velocardio-facial syndrome, CATCH-22)
• Truncus, Tetralogy, Interrupted Aortic Arch
• Need to screen parents.
Neonatal Manifestations of
Congenital Heart Disease
• Heart Murmur (~ 50%)
• Cyanosis and/or Arterial Desaturation using
pulse oximetry
• Pallor or Poor Perfusion
• Tachypnea
• Tachycardia
• Slow growth (FTT)
Heart Murmurs
• ~50% of newborns with significant CHD have
minimal or no murmur at birth (large VSD, single
ventricle, transposition, TAPVR)
• Left to right shunt defects such as large VSD do
not develop murmurs until the PVR drops (days to
weeks
Cardiac murmur is an insensitive marker for CHD
Grading Heart Murmurs
1 Softer than Heart Sounds
2 Equal to Heart Sounds
3-6
Louder than Heart Sounds
The Cardiac Exam
• Observation
• Palpation (precordium, pulses, perfusion,
liver)
• Auscultation
Listening is just one step. Be as descriptive as
possible.
Heart Murmurs
Remember most cardiac murmurs are benign,
but…
• Factors that increase likelihood of CHD
– Persistence
– Intensity
– Association with any symptoms
Unexplained Tachypnea
• Persistent resting tachypnea (greater than
60/minute) and no murmur
• Need to rule out cardiac etiology
• ~10% of CHD presents with this finding
• Importance of chest X-ray and Pulse Oximetry
Screening tests
• Pulse oximetry
• Chest X-ray
• 4 extremity blood
pressure
• EKG: best used when
concern is cardiac rhythm
Infant with Cardiomegaly
Cyanotic vs. Acyanotic CHD
• Pulse Oximetry!
• The cyanotic infant needs immediate
assessment!
Acrocyanosis
Cyanotic Infant
Oxygen challenge
Lung vs. Heart???
Oxygen supplementation will not correct
pulse oximetry to 100% with cyanotic
congenital heart disease.
Transient Ductus Murmur of
the Healthy Newborn
• Soft systolic murmur, grade 1-2 in intensity, often
higher pitched
• Caused by flow in closing ductus. Typically heard
best at 4-16 hours of life
• Studies indicate that it can be heard in most
newborn infants
• Hallmark of this murmur is its transient nature
• Infants are asymptomatic (normal feeding;
breathing comfortably)
• The Auscultation Assistant - Systolic Murmurs
Delayed closure of PDA in
Premature Infants
• Risk factors include lower gestational age
and finding of RDS
• Should be suspected in any preemie with
respiratory symptoms and new onset murmur
• Larger PDA’s in the sickest preemie infants
are often silent
• CXR: ground-glass or “wet” appearance
Physiologic Peripheral
Pulmonary Stenosis (PPS)
• Murmur of PPS is high pitched
• Heard well in both axillae and into posterior
lung fields
• More common in infants born prematurely
• Infants are asymptomatic
• Resolves by 3-6 months
• CXR, EKG, & Pulse oximetry: normal
Innocent (Still’s) Murmur
• Lower pitched
• Soft, grade 1-2 in intensity
• Described as “musical”, “vibratory”, “twanging”or
“barking seal”
• Often heard best at cardiac apex
• CXR and pulse oximetry normal
• The Auscultation Assistant - Systolic Murmurs
Infant Heart Murmurs
• Asymptomatic Infant with persistent murmur
(feeding well, normal pulse oximetry and
CXR): needs close follow-up, echo/cardiac
referral when appropriate
• Infant with murmur and any other clinical
sign: (tachypnea, decreased pulses,
abnormal CXR, arterial desaturation): needs
evaluation ASAP!
CHD with Left to Right Shunts
(common cause of early cardiac murmurs)
•
•
•
•
VSD
ASD
PDA
AVSD (AV canal defect)
50% of children with CHD will
have one of these defects!
Ventriculoseptal Defect (VSD)
• Most Common Cardiac Defect (35% of all
cardiac defects)
• 50% male:female
• Small defects are detected earlier (1st days of
life) than larger defects
• Murmur is due to systolic pressure difference
between LV and RV
• The Auscultation Assistant - Systolic Murmurs
VSD: Natural History
• ~ 50%: close spontaneously
• ~ 25%: persistent small shunts that do not
require surgery (risk for SBE)
• ~ 25%: require surgical closure
ASD
• Soft systolic murmur, grade 1-2 intensity,
heard in pulmonary listening area (can mimic
the murmur of PPS)
• Typically not heard for several weeks
• Most infants with ASD are asymptomatic
• Mild cardiomegaly on CXR
• Normal Pulse Oximetry
• The Auscultation Assistant - Systolic
Murmurs
ASD: Clinical Findings and
Natural History
• 65% female prevalence
• Murmur frequently sounds benign and is
often overlooked!
• Murmur: due to increased flow across
pulmonary valve
• Spontaneous closure occurs in those
diagnosed in 1st month of life
• PFO (defects < 3 mm) is common and benign
• No risk for SBE
AV Septal Defect
• Also called AV Canal defect or Endocardial
Cushion defect
• ASD, VSD, and commonly AV regurgitation
• Large VSD allows systemic pressure
transmission into pulmonary vascular bed
• Associated with high PVR and systemic RV
pressure (and hence, absent or soft murmur)
Coarctation: Clinical Findings
• Systolic murmur, grade 2 intensity, at left midclavicular area to mid-scapular area
• Diminished lower extremity pulses
• Need for 4-extremity blood pressures
• Difficult diagnosis in the newborn prior to ductal
closure
• 65% male prevalence
• Think possible Turners syndrome in girls with
coarctation
Critical Coarctation (or IAA)
• All pulses diminished with cool mottled
extremities, delayed capillary refill, pallor,
poor perfusion, acidosis, low cardiac output
• Cardiac murmur often minimal; listen for
gallop
• Need for PGE infusion
• Need for cardiac operation
Heart Sounds & Murmurs
• The Auscultation Assistant - Systolic
Murmurs