Rapid Review·Cardiovascular
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HY Approach
T1Must knowApproach to Pediatric Murmurs
Focus on
Most murmurs in children are innocent: soft, musical or vibratory, early- or mid-systolic, louder lying down and softer standing, in a thriving child with a normal examination. Any diastolic, continuous, holosystolic, harsh, grade 3 or louder, radiating or symptomatic murmur — or one with an abnormal S2, a click, weak femoral pulses or cyanosis — gets an echocardiogram. The venous hum is the one innocent murmur that is continuous and louder standing.
Key takeaways
The job
Innocent or pathologic
most children have an audible murmur at some point and fewer than 1 percent have structural disease.- The task is to tell innocent from pathologic at the bedside and echo only the right children.
| Murmur | Character | Site and behavior |
|---|---|---|
| Vibratory Still murmur (the most common innocent murmur) | Low-pitched, vibratory, musical, crescendo-decrescendo systolic | Left lower sternal border; louder supine, softer upright |
| Pulmonary or aortic flow murmur | Soft systolic ejection murmur from a dynamic circulation (fever, anemia, athletes) | Left (pulmonary) or right (aortic) upper sternal border; may radiate to the axilla |
| Cervical venous hum | Low-pitched continuous murmur (systole and diastole), loudest in diastole; turbulence in the internal jugular vein | Supra- or infraclavicular; louder standing, disappears with neck flexion, supine position, or pressure on the jugular vein |
General rules and red flags
Timing
ejection systolic murmurs are likely physiologic; holosystolic, diastolic and continuous murmurs are nearly always pathologic.S1
a holosystolic murmur masks S1; an ejection murmur has an audible S1 followed by the murmur.Quality
musical quality almost always means benign.Red flags that need a workup
murmurs of grade 3 or more or harsh in quality; diastolic or continuous murmurs; holosystolic murmurs; an S3 or S4 gallop; added sounds such as clicks; radiating murmurs; any symptomatic murmur.- Any single pathologic feature warrants electrocardiogram and echocardiography.
| Feature | Benign | Pathologic |
|---|---|---|
| History | Asymptomatic, normal growth, no significant family history | Infants: poor weight gain, respiratory distress, difficulty feeding; older children: exertional fatigue, chest pain, syncope; family history of sudden death or congenital disease |
| Murmur | Early or mid ejection systolic; musical or vibratory; grade 1 to 2; decreases or disappears with standing and Valsalva (less preload) | Holosystolic or diastolic; harsh; grade 3 or more; persists with standing and Valsalva |
| Other findings | Normal vital signs, normal S1 and S2, symmetric pulses | Central cyanosis; a loud, fixed or single S2; weak femoral pulses; hepatomegaly |
| Management | Reassurance | Electrocardiogram and echocardiography |
Which pathologic murmur is which
Holosystolic at the third left space
high-pitched and louder the smaller the defect: Ventricular Septal Defect.Ejection murmur at the left upper sternal border with a widely fixed split S2
a crescendo-decrescendo murmur means Atrial Septal Defect.Harsh continuous machinery murmur at the left second space radiating to the clavicle
Patent Ductus Arteriosus.Harsh ejection murmur at the left upper sternal border with a single S2 and cyanosis
Tetralogy of Fallot.An interscapular murmur with weak femoral pulses
Coarctation of Aorta.An ejection murmur with a click that fades on inspiration
Pulmonary Stenosis.A systolic murmur that gets louder standing in an adolescent
Hypertrophic Cardiomyopathy.A mid-systolic click
Mitral Valve Prolapse.Adult maneuvers
on Heart Sounds & Murmurs.Management
Innocent murmur with a normal history and examination
reassurance, no investigations, no activity restriction, no endocarditis prophylaxis.- Explain that it may come and go with fever and growth.
Any red flag
electrocardiogram and transthoracic echocardiography.A newborn murmur with cyanosis, distress, weak pulses or a failed oximetry screen
evaluated the same day (Approach to Neonatal Cyanosis).A healthy 5-year-old has a soft, musical, grade 2 systolic murmur at the left lower sternal border that is louder lying down and softer sitting up; growth is normal. What is it, and what is the management?
A vibratory Still murmur, the most common innocent murmur. Reassurance only: no electrocardiogram, echo, activity restriction or endocarditis prophylaxis.
How it's tested
A healthy 5-year-old with a grade 2 low-pitched vibratory systolic murmur at the left lower sternal border that disappears when he stands: Still murmur — reassurance, no echo.
A 6-year-old with a continuous humming murmur under the right clavicle that vanishes when she lies down or when you press on her neck: venous hum — innocent.
A 3-month-old with a grade 3 harsh holosystolic murmur, tachypnea, sweating with feeds and poor weight gain: VSD with heart failure — echocardiography.
An asymptomatic 8-year-old with a soft ejection murmur at the left upper sternal border and a widely split S2 that does not move with breathing: ASD — echocardiography; the fixed split is the red flag.
A teenager's systolic murmur gets louder when he stands up: never innocent — hypertrophic cardiomyopathy (or MVP); echo before sports.
Which findings mandate echocardiography in a child with a murmur: diastolic or continuous (non-hum) murmur, holosystolic murmur, grade ≥ 3 or harsh quality, radiation, abnormal S2 or clicks, symptoms, cyanosis, or weak femoral pulses.
Go deeper
Related Step 2 pages: Approach to Congenital Heart Disease, Heart Sounds & Murmurs, Ventricular Septal Defect, Atrial Septal Defect, Patent Ductus Arteriosus, Hypertrophic Cardiomyopathy, Approach to Neonatal Cyanosis
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