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Heart murmurs in children — innocent or pathological
Most murmurs in children are innocent: systolic, soft (grade 2 or less), with a normal S2, no thrill and no symptoms, and they change with position; any murmur that is diastolic, holosystolic, grade 3 or more, with an abnormal S2, weak leg pulses or symptoms — needs echocardiography and referral.
Why it matters in the exam
The question describes a 4-year-old at a routine check with a "musical", vibratory murmur at the left mid-sternal border that gets louder lying down and softer standing — an innocent Still's murmur that needs no work-up. Another case: a continuous murmur below the clavicle that disappears lying down or with pressure on the jugular vein — a venous hum. The distractors offer echocardiography or activity restriction, and the right answer is reassurance.
The warning signs are what the exam wants you to recognise: a fixed split S2 (ASD), a holosystolic murmur heard best at the left lower sternal edge (VSD), a continuous "machinery" murmur (PDA), weak or delayed leg pulses with arm hypertension (coarctation), a systolic click, and a murmur that gets louder on standing and with Valsalva (HCM — an important check before competitive sport). Symptoms such as sweating with feeds, failure to thrive, cyanosis, exertional syncope or exertional chest pain make any murmur suspicious.
In the newborn, a peripheral pulmonary stenosis (PPS) murmur is heard in the axillae and back and disappears by 6 months. On the other hand, the absence of a murmur in a newborn does not exclude significant heart disease — duct-dependent lesions are found by pulse-oximetry screening. The work-up of a suspicious murmur is echocardiography and cardiology referral; a chest X-ray and ECG alone do not replace an echo.
Key points
- Most murmurs in children are innocent.
- Innocent: systolic, soft, normal S2, no symptoms, changes with position.
- Diastolic, holosystolic, grade 3 or more or a thrill → echocardiography.
- Fixed split S2 = ASD; weak leg pulses = coarctation.
- Louder on standing and Valsalva = HCM.
Summary table
| Murmur | Features | When common | Meaning |
|---|---|---|---|
| Still's (innocent) | Vibratory-musical, left mid-sternal border, louder lying down | Age 3–6 | Reassurance, no work-up |
| Venous hum (innocent) | Continuous, below the clavicle, disappears lying down or with neck pressure | Preschool age | Reassurance |
| Pulmonary flow and PPS (innocent) | Soft systolic at the base; PPS in the axillae and back | PPS in the newborn, gone by 6 months | Reassurance and follow-up |
| ASD | Fixed split S2, soft systolic murmur at the base | Any age | Echocardiography |
| VSD | Loud holosystolic at the lower left sternal border, sometimes a thrill | Infancy | Echocardiography; small ones often close |
| Coarctation | Weak leg pulses, high arm blood pressure | Any age | Echocardiography, urgent in the newborn |
| HCM | Louder on standing and with Valsalva, softer on squatting | Adolescents, athletes | Echocardiography, restrict sport until assessed |
Free exam questions
בן 5 שנים נבדק בשל הפרעה קלה בשגשוג. בבדיקתו :לציין דופק 70 לדקה סדיר , אוושה לבבית סיסטולית בעוצמה 2/6 בגבול הסטרנום השמאלי העליון עם פיצול רחב וקבוע ( של קול שני 2 S ) ו בלט פרקורדיאלי קל משמאל . ה דופק ה .פמורלי נמוש היטב ם מה האבחנה והטיפול המתאימים ביותר לממצאים אלו ? (the question as examined, in Hebrew)
- א. אוושה תמימה, פונקציונלית, לא דרוש טיפול
- ב. פגם קטן במחיצה בין החדרים שלא מצריך סגירה
- ג. פגם במחיצה הבין עלייתית המצריך סגירה
- ד. היצרות בינונית של המסתם הריאתי שמצריכה הרחבה
As part of a routine examination, in cardiac auscultation of a 4-month-old boy, a gentle 2/6 systolic murmur was heard, and widely split and fixed S2. Normal oxygen saturation. A chest X-ray demonstrated enlargement of the right atrium and ventricle. What is the likely etiology?
- A. Ostium secundum defect
- B. Transposition of great arteries
- C. Total anomalous pulmonary venous return
- D. Tetralogy of Fallot
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Sources
- Nelson Textbook of Pediatrics, 22nd edition (2024) — History and Physical Examination in Cardiac Evaluation
- AAP/AHA statement on preparticipation cardiovascular screening of young competitive athletes, 2014 (current) — History and examination elements
- Moss and Adams' Heart Disease in Infants, Children, and Adolescents, 10th edition (2021) — Innocent murmurs and the cardiac examination
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.