An innocent heart murmur is a type of functional heart sound commonly found in children. It is harmless and does not indicate heart disease.
What Is a Heart Murmur?
A heart murmur is a sound heard during cardiac auscultation. It is often associated with valve disease or congenital heart defects. However, sometimes the natural turbulence of blood flow through the heart and large vessels can cause a murmur even without structural abnormalities.
What Is an Innocent Heart Murmur?
An innocent murmur, also called a functional or physiological murmur, is a benign sound produced by blood flowing through the heart and large arteries. It is not caused by heart disease and is especially common in childhood.
Most children may have an innocent murmur at some point, especially during fever, physical activity, anxiety, or stress—conditions that increase blood flow and make the murmur more noticeable.
Why Does an Innocent Murmur Occur?
The exact cause of an innocent murmur is not fully understood. It is believed to result from turbulent blood flow in the heart chambers or large arteries. The sound’s intensity is usually related to the speed of blood ejection from the ventricles.
Types of Innocent Murmurs
Innocent murmurs are often systolic, short in duration, low in intensity, and not heard during diastole. The most common types include:
- Still’s murmur: Caused by vibrations of internal structures during systole.
- Venous hum: Caused by blood flow turbulence from the neck veins into the chest veins.
- Pulmonary ejection murmur: Caused by blood flow from the right ventricle into the pulmonary artery.
- Carotid murmur: Due to turbulent blood flow in the carotid arteries.
- Peripheral pulmonary artery murmur: Caused by turbulence at the pulmonary artery bifurcation.
Diagnosis and Management
Innocent murmurs do not require treatment or follow-up if properly diagnosed. A pediatric cardiologist should evaluate any murmur to rule out structural heart disease.
A cardiac ultrasound (echocardiogram) can confirm that the heart structure is normal. If no abnormalities are found, no further tests are needed.
Functional Murmur in Adults
A functional murmur may also be heard in adults, especially during states of increased cardiac output such as fever, pregnancy, or anxiety. Like in children, it is not harmful and does not require treatment.
Conclusion
An innocent murmur is not caused by any heart abnormality, does not produce symptoms, and does not require treatment or medical follow-up. It is a harmless condition, and those who have it can lead a completely normal life.
This article is for informational purposes only. It does not replace professional medical evaluation.
Medical reference: Accidental Heart Murmurs
