Definition
Heart murmur is an extra or abnormal sound that is heard during cardiac auscultation (when your healthcare provider listens to your heart with a stethoscope). A murmur doesn’t cause noticeable effects on its own. Certain heart murmurs are completely harmless and are not associated with any health problems at all. But sometimes a heart murmur is a sign of heart disease, and you may experience fatigue, shortness of breath, or other complications of your heart condition.
If a murmur is detected, the cause can usually be identified with a non-invasive test. If there is a serious cause of your heart murmur, surgical or medical treatment can often correct the problem and prevent complications.
Prevalence of Heart Murmur
The prevalence of heart murmur was 13.7 per 1000 neonate. If a murmur is heard there is a (42.5%) chance of their being underlying structural defects. Therefore, detection of a murmur should prompt early referral for investigation and diagnosis or appropriate family reassurance.
Types of Heart Murmur
All heart murmurs are analyzed for pitch, loudness, and duration. They are also graded, according to their intensity (on a scale of one to six with one being very faint and six being very loud).
Types of murmurs include:
Systolic murmur – Occurs during a heart muscle contraction. Systolic murmurs are divided into ejection murmurs (due to blood flow through a narrowed vessel or irregular valve) and regurgitant murmurs.
Diastolic murmur – Occurs during heart muscle relaxation between beats. Diastolic murmurs are due to a narrowing (stenosis) of the mitral or tricuspid valves, or regurgitation of the aortic or pulmonary valves.
Continuous murmur – Occurs throughout the cardiac cycle.
Risk factors
Abnormal heart murmurs may happen due to various factors, including:
Heart valve disease: This is the result of a defect in the heart’s structure. Some of these conditions can be present at birth or acquired.
Patent ductus arteriosus: This occurs when the opening between the aorta and pulmonary artery does not close after birth, as it should.
Age: Calcium can build up in the heart valves with age. This reduces the opening of the valves, making it harder for blood to pass through them.
Aortic valve defects: Sometimes, the aortic valve becomes dilated or stretched and stops working properly. This causes blood to leak backward, producing a heart murmur. Doctors call this condition aortic regurgitation.
Infective endocarditis: This is a bacterial infection of the heart’s lining, which can also affect the valves. The growth of bacteria will narrow the opening of the valves and affect blood flow through them.
Chronic rheumatic heart disease: People with this condition have chronic inflammation in the heart valves, which affects the function of the valves and, therefore, the blood flow through those valves.
Tumors: Tumors can also form on a heart valve. Tumors in other parts of the heart, such as the left atrium, can cause a heart murmur by affecting the blood flow through the heart.
Septal defects: Arterial and ventricular septal defects mean there are holes in the walls between the upper or lower chambers, respectively.
Other conditions that can cause heart murmurs include:
- Degenerative valve disease
- Left ventricular outflow tract obstruction
- Hypertrophic obstructive cardiomyopathy
- Turner’s syndrome
- Ehlers–Danlos syndrome
- Marfan syndrome
- Noonan syndrome
- Systemic lupus erythematosus
- Congenital rubella syndrome
- Rheumatic fever
- Ebstein’s anomaly
- Mitral valve prolapse
Causes of Heart Murmur
A number of different things can cause a heart murmur.
Many cases will be innocent, but some heart murmurs are caused by a problem with the heart valves. Sometimes people have been born with a heart valve issue. Alternatively, a heart murmur can develop as a result of:
- Stiffening or hardening of heart valves due to age, wear and tear (stenosis), which interrupts normal flow of blood through the valves
- A heart attack
- Infection of the heart valves
- Long term effects of rheumatic fever
Other causes of a heart murmur include:
- Congenital heart conditions (heart conditions that you’re born with)
- Pregnancy
- Fever
- Extreme physical exercise
- Rapid growth
- Anaemia
- Over-active thyroid gland
Symptoms
Innocent heart murmurs have no symptoms. People with abnormal heart murmurs may experience such symptoms as:
- Trouble breathing
- Shortness of breath
- Sweating
- Chest pain
- Fainting
- Skin with a bluish tint
- Weight gain
- Neck veins that bulge
- A chronic cough
Babies and young children with abnormal heart murmurs may also experience:
- Feeding problems
- Excessive fussiness
- Poor growth
- Fast breathing
Heart Murmur complications
An innocent heart murmur has no complications. Complications of an abnormal heart murmur will vary depending on the cause. Possible complications include:
- Heart failure, when the heart is so weak it no longer pumps blood well
- Infection of the heart’s valves or inner lining (infective endocarditis)
- Blood clots and stroke
- Fainting
- Heart attack
- Sudden cardiac arrest, is when the heart suddenly stops beating
Diagnosis and test
Your doctor will listen to your heart with a stethoscope to see if you have a heart murmur. If they think it could be an abnormal heart murmur, your healthcare team may arrange tests like:
Chest X-ray: A chest X-ray takes pictures inside your chest to find any structural problems.
Echocardiogram: Echocardiogram (also called an echo) uses sound waves to create images of your heart’s valves and chambers. It helps examine your heart’s pumping action. This can be a surface ultrasound or a more specialized ultrasound procedure through your mouth and esophagus, which gives better pictures than the surface ultrasound.
Electrocardiogram: Electrocardiogram (also called an ECG or EKG) is a painless test that measures the electrical activity of your heart.
These tests are very common, but you can speak to your doctor if you feel worried about having them.
Treatment and medications
Treatment depends on the cause but may include:
Innocent heart murmurs – No treatment is necessary, as the heart structures and blood flow are normal – just noisy.
Heart surgery – To repair leaking heart valves, or repair the structural abnormalities of congenital heart disorders. This may require open heart surgery.
Endocarditis or other infections – Antibiotics, and surgery in some cases.
Anaemia – Can often be treated with iron supplements and changes to diet. Depending on the cause, more serious cases of anaemia may need treatments including blood transfusions or removal of the spleen (splenectomy).
Hyperthyroidism – Medications or surgery to bring the thyroid hormone levels back to normal.
Medications
Medications that might be used to treat heart conditions associated with murmurs include:
Blood thinners (anticoagulants): This type of medicine prevents blood clots. Some conditions that cause heart murmurs are closely linked to irregular heartbeats (arrhythmias) that can cause blood clots. Blood clots increase the risk of strokes. Blood thinners include warfarin (Jantoven), clopidogrel (Plavix), apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa) and others.
Water pills (diuretics): This medicine removes excess fluid from the body. A diuretic may be given to treat high blood pressure or other conditions that can make heart murmurs worse.
Angiotensin-converting enzyme (ACE) inhibitors: This type of drug lowers blood pressure. High blood pressure can worsen underlying conditions that cause heart murmurs.
Beta blockers: A beta blocker lowers heart rate and blood pressure.
In the past, many people with worrisome heart murmurs were told to take antibiotics before surgery or dental procedures to prevent certain heart infections. That recommendation has changed. Antibiotics are only recommended in specific situations. For instance, they may be recommended for people with artificial heart valves, a history of heart valve infections or congenital heart defects that increases the risk of infection inside the heart.
Surgery or other procedures
If medications don’t help, surgeons can aggressively treat underlying problems of heart murmurs. Some examples of surgeries include:
Balloon valvuloplasty is used to treat narrowed or stiff (stenotic) heart valves. During this procedure a catheter (long, thin, flexible tube) is directed through a vein in the groin to the heart valve that needs to be opened. A large balloon at the tip of the catheter is inflated to open the valve. The balloon is then deflated and removed.
Heart Valve Repair may be an option for some patients. This is more common with the mitral valve and can be done through minimally invasive, robotically guided procedures that decrease complications while allowing for a quicker recovery.
Heart Valve Replacement for stenosis is performed using either a bioprosthetic (tissue) heart valve that is made from natural sources (e.g., pig, cow or human) or a mechanical heart valve. The advantage to a bioprosthetic valve is that it does not contain metal and therefore blood thinners are not needed long term. Mechanical valves contain substances that are more likely to form blood clots and require the use of blood thinners. The advantage, however, is that they last for many years.
Transcatheter aortic valve replacement (TAVR) uses a catheter to replace the aortic valve in select patients with severe aortic stenosis (narrowing of the aortic valve opening) who can’t tolerate, or are high-risk candidates for, open heart surgery.
Annuloplasty is an option if the base of a mitral or tricuspid valve becomes enlarged, dilated, or damaged. This procedure is performed to strengthen the ring of tissue (called the annulus) by sewing in an O- or C-shaped annuloplasty ring at the valve base.
Lifestyle Changes for Heart Murmur
Doctors used to give anyone with a heart murmur antibiotic medicines before a dental or surgical procedure to prevent infection in your heart valves. (Some of these procedures may cause bacteria to enter the bloodstream, which can lead to infection.) Today, most doctors do not recommend routine antibiotics unless the murmur is caused by intrinsic valve disease. Talk to your doctor or dentist for current guidelines.
Prevention
In most cases, you can’t prevent heart murmurs. The exception is that if you treat an underlying condition, such as high blood pressure, or you avoid heart valve infection, heart murmurs are stopped before they start.