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Systolic Heart Murmur: Causes, Symptoms, and Management Strategies

Writer: Dr. Baraa Alnahhal
Dr. Baraa Alnahhal
Oct 7
7 min read

Updated: 4 days ago

Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026

TL;DR: A systolic heart murmur is an irregular sound heard when the heart muscle contracts. While many murmurs are "innocent" and harmless, others may indicate underlying structural issues like valve stenosis or septal defects. Diagnosis involves physical exams and imaging, with treatment ranging from monitoring and medication to surgical intervention depending on the severity and cause.

When to get checked urgently: A murmur together with chest pain, severe shortness of breath, or fainting needs prompt medical attention. If symptoms are severe or sudden, call your doctor or emergency services immediately.

Quick Answer

What is a systolic heart murmur?

A systolic heart murmur is a "whoosh" or "swish" sound occurring during the heart's contraction phase (systole). It results from turbulent blood flow and is categorized as either functional (innocent) or organic (abnormal). While some people experience no symptoms, others may face fatigue or shortness of breath. Diagnosis typically begins with a stethoscope exam, followed by tests like echocardiograms. Treatment depends on the underlying cause and may include blood pressure medications or valve repair.

Medical illustration of the heart and its valves with a waveform showing the timing of a systolic murmur between the first (S1) and second (S2) heart sounds during systole.
A systolic murmur occurs between the first and second heart sounds, while the heart muscle contracts.

What the research says

  • Many adults with an "asymptomatic" systolic murmur have significant heart disease. In a review of 1,221 adults referred to a heart murmur clinic (980 had echocardiography), significant cardiac disease was found in 156 patients and 23 needed surgery over 5 years. Aortic stenosis (43 patients) and mitral regurgitation (48) were most common, and structural heart disease was more likely in people over 65 (16% vs 11%, P < 0.05) (Kueh et al., Intern Med J, 2017).

  • Most childhood murmurs are innocent, but not all. Among 150 children referred for asymptomatic murmurs, 19% (28 children) had congenital heart lesions on echocardiography. Of the 72 whose murmur had been judged innocent by general pediatricians, 2 (3%) had heart disease (Sackey, Cardiol Young, 2016).

  • How a murmur sounds helps point to the cause. A review of the clinical examination found that detecting systolic murmurs was only fairly reliable between examiners (kappa 0.30 to 0.48). A murmur that peaks in mid to late systole was a strong clue to aortic stenosis (positive likelihood ratio 8.0 to 101), while the absence of radiation to the right carotid artery helped rule it out (negative likelihood ratio 0.05 to 0.10) (Etchells et al., JAMA, 1997).

What Is a Systolic Heart Murmur?

A systolic heart murmur is an unusual sound, often described as a "swish" or "whoosh," that occurs during the first part of a heartbeat when the heart muscle contracts. This phase is known as systole. The sound is caused by turbulent blood flow as it moves through the heart's chambers or across its valves.

Normally, a heartbeat consists of two primary sounds: the closure of the atrioventricular valves (mitral and tricuspid) followed by the closure of the semilunar valves (aortic and pulmonic). A systolic murmur typically occurs after the first heart sound. While many of these sounds are not dangerous, they can sometimes be a sign of a structural issue within the heart. To learn more about how heart valves can be affected, see our guide to heart valve disease.

Types of Systolic Murmurs

Healthcare professionals categorize systolic murmurs based on their cause and the heart structures involved. Understanding these distinctions is vital for determining the appropriate care path.

Murmur Category

Description

Functional (Innocent)

Occurs in individuals with a healthy heart structure; often harmless.

Organic (Abnormal)

Results from an underlying issue with the heart's physical structure.

Ejection Murmurs

Typically start in the semilunar valves (aortic or pulmonic); can be functional or organic.

Regurgitant Murmurs

Occur when heart valves don't close properly, causing blood to leak backward; always organic.

Common Causes and Risk Factors

Systolic murmurs are often linked to specific conditions that affect how blood flows through the heart. These causes are generally divided between ejection and regurgitant mechanisms.

Ejection Murmur Causes

Ejection murmurs are frequently caused by narrowing in the heart's exit points or holes in the walls separating the upper chambers.

  • Aortic Stenosis: A narrowing of the aortic valve that restricts blood flow from the heart to the aorta.

  • Atrial Septal Defect (ASD): A hole in the wall separating the heart's two upper chambers (atria).

  • Hypertrophic Obstructive Cardiomyopathy (HCM): A genetic condition where the wall between the lower chambers thickens.

  • Pulmonic Stenosis: Narrowing in the valve connecting the heart to the lungs.

Regurgitant Murmur Causes

Regurgitant murmurs occur when blood leaks backward through valves that should be closed.

  • Mitral Valve Regurgitation: Blood leaks backward into the left atrium during contraction.

  • Tricuspid Valve Regurgitation: Blood leaks backward into the right atrium.

  • Ventricular Septal Defects (VSD): A hole in the wall separating the heart's lower chambers (ventricles).

Infographic of common causes of systolic heart murmurs: ejection murmur causes such as aortic stenosis and septal defects on one side, and regurgitant murmur causes such as mitral and tricuspid valve leakage on the other.
Ejection murmurs often come from narrowing or septal defects, while regurgitant murmurs come from leaking valves.

Recognizing the Symptoms

Many individuals with heart murmurs do not experience any noticeable symptoms. However, when a murmur is a sign of an underlying condition, several physical indicators may appear.

  • Physical Appearance: A bluish tint to the skin (cyanosis).

  • Respiratory Issues: Shortness of breath (dyspnea) or a chronic, long-lasting cough.

  • Neurological Signs: Fainting (syncope), lightheadedness, or persistent dizziness.

  • Systemic Effects: Unusual fatigue or fluid retention (edema) in the legs.

Diagnosis and Clinical Testing

The diagnostic process usually begins with a physical examination. A provider uses a stethoscope to listen to the heart's rhythm, pitch, and volume. They also assess how the sound changes when a person shifts their physical position.

To determine the exact cause and severity, several advanced tests may be recommended:

  1. Echocardiogram: Uses ultrasound waves to create a moving image of the heart's structures.

  2. Electrocardiogram (EKG): Records the electrical activity and rhythm of the heart.

  3. Chest X-ray: Provides images of the heart, lungs, and surrounding bones.

  4. Cardiac Catheterization: A procedure where a small tube is used to examine the arteries and heart chambers directly.

The Murmur Grading Scale

Providers use a standardized scale to measure the intensity of a systolic murmur, ranging from one to six.

Grade

Intensity Level

Grade 1

The quietest sound; can only be heard with extra effort by the clinician.

Grade 2

Faint, but audible.

Grade 3

Moderately loud.

Grade 4

Very loud.

Grade 5

Extremely loud; audible with one edge of the stethoscope touching the chest wall.

Grade 6

The strongest and most intense sound; audible with the stethoscope just removed from the chest wall.

Management and Treatment Options

Treatment for a systolic heart murmur depends entirely on whether it is "innocent" or "abnormal." Innocent murmurs typically require no intervention and may resolve on their own. Abnormal murmurs require managing the underlying condition through medication or surgery.

Medication

Commonly prescribed medications focus on reducing the heart's workload and preventing complications (to understand what blood pressure numbers mean, see our guide to normal blood pressure by age):

  • ACE Inhibitors: Used to lower blood pressure.

  • Beta-Blockers: Reduce heart rate and blood pressure.

  • Blood Thinners: Prevent the formation of blood clots.

  • Diuretics: Help the body remove excess fluid.

Surgical Procedures

In severe cases, structural repairs may be necessary to restore proper blood flow. This can include valve repair to tighten or open a valve, valve replacement using mechanical or tissue components, or open-heart surgery to repair septal defects.

Overview of systolic heart murmur management showing diagnosis with a stethoscope, medications such as ACE inhibitors and beta-blockers, and valve repair or replacement.
Management ranges from diagnosis and monitoring to medication and valve repair or replacement.

Conclusion and When to Seek Help

A systolic heart murmur is a common clinical finding that ranges from a harmless sound to a sign of significant heart disease. By understanding the different types and causes, individuals can work with their healthcare providers to monitor their heart health effectively. Early diagnosis through standard testing ensures that abnormal murmurs are managed before they lead to more serious complications.

When to seek help: If you or a loved one has been told you have a heart murmur, or if you are experiencing symptoms like unusual fatigue or shortness of breath, schedule a consultation with a healthcare professional. A thorough evaluation is the best way to ensure your heart is functioning at its best.

Frequently Asked Questions

No, many systolic murmurs are "innocent" and do not indicate a heart problem.

Generally, no. Most murmurs are only detectable by a trained professional using a stethoscope.

Systole refers to the phase of the heartbeat when the heart muscle contracts and pumps blood.

Some causes, like hypertrophic obstructive cardiomyopathy, are genetic, but many others are acquired.

Yes, many children have innocent murmurs that they eventually outgrow.

Systolic murmurs occur during heart contraction, while diastolic murmurs occur during heart relaxation.

For innocent murmurs, no changes are usually needed. Abnormal murmurs may require specific heart-healthy habits.

Stress can increase heart rate and blood flow, which might make a functional murmur more noticeable.

Not necessarily. Grade refers to loudness, not the severity of the underlying condition, although in children a murmur of grade 3 or higher is one of the features that makes a pathologic murmur more likely.

A physical exam is immediate, but imaging tests like echocardiograms may take a few days for results.

Yes, the increased blood volume during pregnancy can sometimes cause a functional systolic murmur.

It is the sound of blood moving turbulently through the heart.

Yes, regurgitant murmurs indicate blood is leaking backward, which is considered organic.

Innocent murmurs often resolve, especially those found in children or caused by temporary conditions.

You should seek medical advice if you experience symptoms like chest pain, shortness of breath, or fainting.

References

Medical Disclaimer

This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition, and never delay seeking professional advice because of something you have read here. If you think you may have a medical emergency, call your doctor or emergency services immediately.

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