medical and health sciences

💓 What’s That Sound? Understanding Heart Murmurs in Newborns and Children

Shadeacademia

14 Apr 2025 • 4 min read

Health & Sciences | The Varrock Street Journal

Happy Monday, Varrok Street Journal readers!
This week’s topic comes from a sound many healthcare professionals know well: the subtle “whoosh” that interrupts the rhythm of a beating heart. Known as a heart murmur, this sound can alarm parents when first discovered in a newborn or child. But here’s the good news—not all murmurs are a cause for concern.

Today, we’ll explore the types of heart murmurs, what causes them, how they’re detected, and what they can mean for your child’s health. Whether you’re a parent, a student, or just curious about how the heart works, this is one you won’t want to miss!

❤️ What Is a Heart Murmur?

A heart murmur is the sound of turbulent blood flow through the heart or nearby vessels, picked up during a physical exam using a stethoscope. It’s often described as a "whooshing" or "swishing" sound, and it can occur during systole (when the heart contracts) or diastole (when it relaxes).

Murmurs are not a diagnosis, but rather a finding. They can be innocent (harmless) or pathological (indicative of a heart problem).

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Turbulence refers to irregular or disrupted blood flow within the heart or blood vessels, often caused by changes in pressure, velocity, or structural abnormalities. This disturbance creates the "whooshing" sound heard during a heart murmur.

👶 Types of Murmurs in Newborns and Children

1. Innocent (Physiologic) Murmurs

These are common and harmless, found in up to 50–70% of children at some point. The heart is normal, and the sound is due to blood flowing rapidly through a healthy heart.

✅ Key Features:

Soft, low-pitched
Changes with position (louder when lying down, softer when standing)
No symptoms (child is active, growing normally)

🗣️ Common Innocent Murmurs:

Still’s murmur: Musical or vibratory, heard best at the lower left sternal border
Pulmonary flow murmur: Soft, blowing sound at the upper left sternal border
Venous hum: Continuous sound heard over the neck veins, changes with head position

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For example, lying down increases blood return to the heart, making the murmur louder, while standing up reduces blood flow, making it softer. This change in flow helps create the shifting sound doctors hear.

2. Pathologic Murmurs

These murmurs indicate a structural problem in the heart and require further evaluation by a cardiologist.

⚠️ Key Features:

Louder (> Grade III/VI)
Associated with other signs: cyanosis, poor feeding, shortness of breath, failure to thrive
Doesn’t change with position

🫀 Common Pathologic Murmurs:

Ventricular Septal Defect (VSD): Harsh holosystolic murmur heard at the lower left sternal border
Atrial Septal Defect (ASD): Systolic murmur with fixed split of S2
Patent Ductus Arteriosus (PDA): Continuous "machine-like" murmur best heard under the left clavicle
Tetralogy of Fallot: Harsh systolic murmur from pulmonary stenosis; may present with cyanosis

Photo Sources from: https://www.achaheart.org/your-heart/educational-qas/types-of-heart-defects/atrial-septal-defect/

🩺 How Are Murmurs Evaluated?

When a murmur is detected, clinicians assess:

Grade (I–VI): Indicates loudness
Timing (systolic, diastolic, continuous)
Location and radiation
Changes with position
Associated symptoms

If a murmur is suspicious, doctors may order:

Echocardiogram (ECHO) – ultrasound of the heart
Chest X-ray – to check heart size
Electrocardiogram (EKG) – to evaluate rhythm

🧠 Why This Matters

For many parents, hearing that their baby has a heart murmur can be frightening. But the majority are innocent and resolve with age. Recognizing which murmurs need attention helps:

Avoid unnecessary anxiety and testing
Ensure early diagnosis of congenital heart disease
Promote informed, compassionate pediatric care

🌟 Spotlight on the Future

Advancements in pediatric cardiology are making evaluations faster and more accurate:

Portable handheld ultrasounds now allow point-of-care heart imaging in clinics
AI-assisted auscultation tools are being developed to help doctors classify murmurs
Genetic screening in newborns with pathologic murmurs is guiding personalized treatment for congenital heart defects

😲 Did You Know?

The Still’s murmur, the most common innocent murmur, was named after Dr. George Frederic Still in the early 1900s.
Many innocent murmurs disappear by age 7, but some persist into adolescence.
Congenital heart defects are the most common birth defect—affecting 1 in 100 babies!

Here is a video discussing all types of murmurs if you would like to know more!

🧠 Reflection Questions

Why might heart murmurs cause anxiety despite often being benign?
What role could AI and digital stethoscopes play in rural or underserved areas?
How can healthcare professionals better communicate the difference between innocent and pathologic murmurs to families?

👋 Final Thoughts

Whether it’s a quiet hum or a more urgent sound, heart murmurs are a message from the heart. Knowing how to interpret them helps ensure that every child gets the care they need—when they need it.

📚 References:

Adult Congenital Heart Association. (n.d.). Atrial septal defect. https://www.achaheart.org/your-heart/educational-qas/types-of-heart-defects/atrial-septal-defect/

American Heart Association. (2023). Heart murmurs in children. https://www.heart.org/en/health-topics/congenital-heart-defects/heart-murmurs-in-children

Mayo Clinic. (2024). Heart murmurs. https://www.mayoclinic.org/diseases-conditions/heart-murmurs/symptoms-causes/syc-20373171

Friedman, K. G., & Alexander, M. E. (2019). Approach to the pediatric heart murmur. New England Journal of Medicine, 380(3), 246-257.

📲 Stay informed and curious

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