- A heart murmur heard in the neonatal period may represent an innocent flow murmur from branch pulmonary arteries, be associated with transitional circulation (closing PDA), or with congenital heart disease.
- However, it must be remembered that not all infants with congenital heart disease have a heart murmur in the neonatal period.
- A neonate with any of the following findings needs urgent senior Paediatrician or Neonatologist (Resident middle grade or Consultant) assessment even if a murmur is not present:
- signs of heart failure or shock (see below),
- lower limb saturations <96% in the absence of respiratory disease,
- failed newborn pulse oximetry screening,
- absent/weak femoral pulses.
Heart murmurs in the neonate: an approach to the neonate with a heart murmur (1279)
Warning
What's new / Latest updates
Summary of Changes in May 2026 Review
- Insertion of paragraph highlighting routine pulse oximetry screening in all newborn babies.
- Parameters for further investigation adjusted to bring into line with GG&C guidance on routine pulse oximetry screening in newborns.
Audience
This guideline is applicable to medical and nursing staff caring for neonates in the West of Scotland.
Investigation will vary depending upon local resources and expertise. The following recommendations represent the minimum requirements to ensure the safe management of neonates with heart murmurs and the timely identification of congenital heart disease.
- All infants with a heart murmur on neonatal examination should be reviewed by a paediatric middle grade doctor or consultant.
- All infants with a heart murmur should remain in hospital until >24 hours old (unless definitive diagnosis is reached before this).
- All infant with a heart murmur should have a detailed cardiovascular clinical examination which must include measurement of pre and post ductal saturations.
- If a baby with a heart murmur is discharged before a definitive diagnosis is reached, the parents should be given a written information leaflet (Appendix 2) describing warning signs and advising them of what to do in the event that their baby became unwell. Ensure an appropriate contact telephone number is given to parents e.g. the phone number for their local neonatal unit.
Clinical examination:
- Dysmorphic features
- Signs of heart failure (tachypnoea, increased respiratory effort, hepatomegaly, shock)
- Palpation of brachial and femoral pulses
- Presence of cyanosis
- Heart sounds
- Murmur – intensity, character, location and radiation
Routine Pulse Oximetry Screening
- As per the NHS Greater Glasgow & Clyde guidance for postnatal saturation screening, a pre or postductal saturation reading of less than 95% OR a difference of greater than or equal to 3% between pre and postductal saturations warrants further investigation.1
Electrocardiogram
- ECG has been shown to be a sensitive and specific tool for diagnosing atrioventicular septal defect2 (more common in infants with Trisomy 21) but has not been shown to aid significantly in the diagnosis of other structural congenital heart disease 3. It is not necessary to perform an ECG as part of the routine assessment of a baby with a heart murmur.
- If performed, a normal neonatal ECG shows right axis deviation because of the right ventricular dominance of the newborn heart. Left axis deviation in a newborn is a significant abnormal finding and should prompt further investigation.
- Whilst an abnormal ECG should prompt further investigation, a normal ECG should not be considered reassuring if there are abnormal clinical findings or lower limb saturations <96%.
CXR and 4 limb blood pressure
There is no evidence to support the use of CXR or 4 limb blood pressure measurements in the assessment of neonates with heart murmurs 3,4,5,6.
Echocardiography
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This is the gold standard specialist investigation (undertaken by Paediatrician with Expertise in Cardiology (PEC), Paediatric Cardiologist or Cardiac Physiologist qualified to perform congenital Echocardiography) for differentiating between innocent and pathological murmurs. In neonatal units without the specialist expertise to undertake congenital echocardiography on site, information gathered from examination findings and oxygen saturations should be used to determine the need for and timing of follow up +/- referral to paediatric cardiology services.
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Neonatologist Performed Echocardiography (NPE) is an important diagnostic tool but should not be used as a substitute for congenital Echocardiography, and clinical criteria for referral to Cardiology should be applied even if NPE findings are reassuring.
1. Likely significant congenital heart disease – urgent NICU admission
Infants with a heart murmur and any of the following warning signs: failed newborn pulse oximetry screening; absent/weak femoral pulses; signs of heart failure or shock. These infants require immediate admission to a neonatal unit for consideration of prostaglandin and urgent discussion +/- transfer to a cardiac centre. If appropriately skilled local PEC or visiting cardiologist is available to perform congenital echocardiogram while retrieval is awaited then this can be done to inform immediate management. This should not delay transfer
2. Asymptomatic but clinically pathological murmur – soon congenital echocardiogram (pre-discharge or as an urgent outpatient appointment)
Infants without any of the above warning signs but with any of the following abnormal clinical findings: dysmorphism; abnormal heart sounds; loud murmur (>3/6); pansystolic, diastolic, continuous murmur; murmur location other than left sternal edge/radiation.
3. Low risk of congenital heart disease - routine review neonatal OPC 4-6 weeks
Well infants with no signs of heart failure, normal pulses, baby passed routine pulse oximetry screening (i.e. a saturation reading of 95% or above in both limbs or a difference of less than 3% between pre and post ductal saturations), soft (1-2/6) systolic murmur at the left sternal edge with no radiation
