Table 3.

An abridged differential diagnosis of paediatric heart murmur by murmur location^8–11

Timing	Location	Differential diagnosis	Key murmur features and associated physical findings	Important points to consider
Systolic ejection	Left upper sternal border	Innocent pulmonary flow murmur	This murmur is not harsh in character. No symptoms.	This can be accentuated by high cardiac output states such as fever, anaemia, pregnancy, and thyrotoxicosis.
		Innocent pulmonary branch murmur of infancy	Radiates to axillae and back. No symptoms.	Characteristic time course in which the murmur can appear in the first few days postnatally, and resolves by several months of age.
		Pulmonary valve stenosis (PS)	Variable systolic ejection click. Can radiate to axillae and back. When more than mild PS, there can be increased right ventricular precordial impulse.	Most cases are sporadic. Common with Noonan syndrome. The murmur of PS sometimes appears before the cyanosis, and so can be the first clinical feature recognized in tetralogy of Fallot.
		Atrial septal defect (ASD)	Wide and fixed split 2nd heart sound. Diastolic flow rumble over tricuspid valve and systolic flow murmur over pulmonary valve. Increased right ventricular precordial impulse.	Most ASD is sporadic. There is a strong female predisposition. Holt-Oram syndrome and thrombocytopenia absent radius are both rare, but highly associated with ASD
		Mammary souffle	Often bilateral. Disappears with firm pressure from stethoscope	Occurs during pregnancy and lactation
	Right upper sternal border	Aortic stenosis	Often associated with constant early systolic ejection sound. Radiates to neck. Can be associated with palpable thrill	Common with Turner syndrome, with or without aortic coarctation. Nonsyndromic bicuspid aortic valve commonly recurs in family members. Occasionally rheumatic.
		Subaortic stenosis	Also can be maximal at the left upper sternal border. When obstruction is dynamic, this murmur increases with standing and during Valsalva strain, and decreases with recumbent position, squatting, or isometric handgrip exercise.	Occurs in fixed and dynamic forms. The dynamic form is generally in association with hypertrophic cardiomyopathy.
	Left lower sternal border and towards apex	Stills murmur	A very musical, vibratory, low pitched sound, with multiple harmonics. Diminishes in the sitting position.	Can occur at any age, but is extremely common in the preschool and young school age population.
	Midback	Innocent pulmonary branch murmur of infancy	See above	See above
		Pulmonary branch stenosis	If severe, the right ventricular impulse on the chest wall can be increased in intensity.	Rare as an isolated lesion. Has associations with Williams syndrome and maternal rubella
		Aortic coarctation	Decreased pulse intensity in the lower extremities. Arm-leg systolic BP difference. When obstruction is severe there can be heart failure symptoms in early infancy, Murmur over the back and in the left axilla.	Common with Turner syndrome.
Holosystolic	Left mid-sternal border	Ventricular septal defect (VSD)	High pitched and loud when the defect is small. Lower pitched and softer when defect is large. Large defects often have diastolic flow rumble (see below).	Defects can occur in several locations in the ventricular septum, most commonly muscular and perimembranous, but also inlet as in atrioventricular septal defect (AVSD) and subarterial. Clinical examination cannot identify location with confidence.
	Left lower sternal border	Tricuspid valve regurgitation	Low pitched when right ventricular systolic pressure is normal. High pitched in the setting of pulmonary hypertension. Increases with inspiration.	Can occur in association with Ebstein’s anomaly or non-specific tricuspid valve dysplasia. The tricuspid valve may leak in AVSD.
	Apex	Mitral regurgitation	High pitched. Can have an associated mid- to late-systolic click when valve prolapses. Augmented when standing.	The mitral valve may leak in AVSD. Can be associated with Marfan syndrome. Other congenital anomalies of the mitral valve are unusual. This is the most common valve affected by rheumatic fever.
Continuous	Left infraclavicular, upper- and left mid-sternal border	Patent ductus arteriosus (PDA)	Bounding pulses (wide pulse pressure) and increased left ventricular impulse when ductus is large. Late systolic accentuation.	Functional closure of the ductus arteriosus is usually complete by 3 days after birth. Premature infants are particularly prone to persistent PDA.
		Mammary souffle	Pregnancy, lactation.	Usually identifiable in the appropriate context
		Coronary artery fistula	Often no other features. If large, signs and symptoms of heart failure can be present	This is rare
	Midback	Aortic coarctation	Late in the unmodifed natural history of coarctation of the aorta, the murmur becomes continuous due to growth of collateral circulation.	See above
	Right upper sternal border	Venous hum	Disappears when recumbent, or with ipsilateral jugular pressure.	Very common in children old enough to sit during examination; can persist into adulthood.
Diastolic decrescendo	Left upper sternal border	Aortic regurgitation (AR)	High pitched, decrescendo. Increases with sudden squatting. Longer when regurgitation is more severe. Associated with bounding pulses (wide pulse pressure) when moderate or severe.	Commonly present with bicuspid aortic valve. Less commonly can be rheumatic.
		Pulmonary regurgitation (PR)	High pitched when associated with pulmonary hypertension (Graham-Steele murmur). Low pitched and very common in the setting of surgically modified tetralogy of Fallot.	Congenital pulmonary valve disease producing audible PR is very unusual.
Diastolic rumble	Apex	VSD (large)	VSD large enough to produce a diastolic rumble will often also have increased precordial activity and signs and symptoms of heart failure. A loud P2 can mean pulmonary hypertension	Not impossible to have large muscular or subarterial VSD, but most large VSDs are either perimembranous, outlet malalignment as in double outlet right ventricle, or inlet as in AVSD.
		Mitral valve disease	Can have opening snap, especially if rheumatic.	Can be congenital or rheumatic. A diastolic rumble can occur without true stenosis if there is severe MR. Rheumatic mitral stenosis is progressive over time.
		AR	The so called Austin Flint murmur is of debatable cause, but usually indicates more than mild AR.	See above
	Left lower sternal border	ASD	Also with systolic murmur (see above), fixed split S2, and increased right ventricular impulse.	See above