Heart Murmur: What It Means | Prof. Dr. Umuttan Doğan

One sentence at a routine appointment, or at one you went to for something else entirely, is enough: “I can hear a heart murmur.” In most people that sentence does not mean a serious illness. It is an examination finding, not a diagnosis. But what it is a finding of does need looking into. This article explains what a murmur tells you in adults, what the words in your report mean, and how the decision is reached.

What Is a Murmur, and What Is the Doctor Hearing?

A working heart makes two normal sounds, produced as the valves close. A murmur is an additional sound, heard between those two or laid over them.

It comes from the way the blood is flowing. Blood moving along a smooth path is silent. Passing through a narrowed opening, leaking back the wrong way, or simply flowing faster than usual makes the flow disordered. That disordered flow is called turbulent blood flow, and it is what is heard through the stethoscope.

So a murmur does not say the heart is diseased. It says the blood passing through it is making a sound somewhere. The cause of that sound may be an innocent increase in speed, or it may be valve disease.

What Is an Innocent Murmur?

An innocent murmur is one heard although there is nothing wrong with the structure of the heart. It comes from blood moving through a healthy heart fast enough for the flow to become audible. It is also called a physiological or functional murmur.

Innocent murmurs have characteristic features: they are soft, heard during the heart’s contraction, change with body position, and come with no symptoms at all. Because the structure of the heart is normal they need no treatment, no medicines, and no restriction of sport or daily life.

Things that make a murmur appear for a while

In an adult, the cause of a “new” murmur is sometimes not the heart but something else speeding the heart up. These are called high-flow states:

Anaemia. When the blood count falls the heart pumps harder and faster, and the sound of the flow can become audible.
Pregnancy. The volume of circulating blood rises in pregnancy, and a murmur is heard in a considerable proportion of healthy pregnant women.
Febrile illness. A fever raises the heart rate, and the murmur may disappear once the fever settles.
An overactive thyroid. Thyroid overactivity speeds the heart up.

All of these are correctable and all of them show on a blood test. That is why a blood count and thyroid tests are among the first things asked for when a murmur is heard.

What Do Murmur Grades Mean?

If you have seen something like “grade 2/6 systolic murmur” in your report, that is the scale of murmur grades. It has six steps and it describes the loudness of the sound the doctor heard.

Roughly: 1/6 is the faintest sound, heard only on careful listening; as the grade rises the sound becomes more obvious, the upper steps come with a vibration that can be felt by hand, and at the top step, 6/6, it can be heard without the stethoscope being fully placed on the chest.

Here is the point that gets misunderstood: the grade describes how loud the sound is, not how serious the disease is. A loud murmur draws more attention and does need investigating, but that does not make a faint one unimportant. A significant valve narrowing can produce a soft sound, and innocent flow can produce an obvious one.

What settles the question is not the grade but seeing where the sound comes from.

Systolic or Diastolic? The Other Words in Your Report

A murmur is named after the phase of the cardiac cycle in which it is heard:

Systolic murmur: Heard in the phase where the heart contracts and pushes blood out. It is the commonest kind in adults, and very nearly all innocent murmurs are in this group.
Diastolic murmur: Heard in the phase where the heart relaxes and fills. It is not regarded as innocent and always needs investigating.

The report may also say where the sound was clearest on the chest and where it carried to. These are the first clues as to which valve is involved, but the test that settles it is the echocardiogram.

Can a Murmur Be a Sign of Heart Valve Disease?

It can. In adults the commonest reason for a murmur that needs investigating is heart valve disease, and most valve conditions progress silently for years. A sound heard on examination in someone with no symptoms at all may be the first and only finding.

The pictures seen most often are these:

Aortic valve narrowing. The valve opening narrows and blood passes with difficulty. It becomes more common with age. The catheter treatment is called TAVI.
Mitral valve leak. The valve does not close fully and blood leaks backwards. In suitable patients the catheter method TEER may come into question. The same method is used for a tricuspid valve leak.
Mitral valve narrowing. In Türkiye its commonest cause is past rheumatic heart disease. Where the valve structure is suitable it can be widened with balloon valvuloplasty.
A hole in the heart. An opening between the chambers, present from birth, can be noticed for the first time in adult life. It can be closed with a catheter through ASD and VSD closure.

Which of these is involved, and whether treatment is needed, cannot be said from the sound of the murmur. The detail of the methods is on the heart valve treatments page.

Which Symptoms Make a Murmur Important?

If one of the following is present alongside the murmur, the assessment should not be left waiting:

Breathlessness on exertion. First on stairs and slopes, then on lighter effort: this is the commonest first symptom of valve disease.
Tiredness on exertion and loss of stamina. Things that used to be easy becoming hard is a finding most patients put down to age.
Chest pain or a feeling of pressure.
Fainting, or nearly fainting. If it happens during exertion in particular, it should be assessed without delay.
Swelling of the ankles, or waking at night short of breath.
Palpitations or an irregular pulse.
A diastolic murmur, or a murmur that has become markedly louder than at a previous examination.

A murmur heard in someone with no symptoms is investigated too; the difference is in how urgently.

Which Tests Are Asked for?

The order is usually this:

Echocardiogram. This is the test at the centre of the assessment. It is an ultrasound picture of the heart, and it shows the structure of the valves, the degree of any narrowing or leak, the size of the chambers and the heart’s pump function. Whether the murmur is innocent or due to a condition is established with this test.
ECG. Shows the rhythm and any signs of strain on the chambers.
Blood tests. A blood count and thyroid tests look for correctable causes that could explain the murmur.
Chest X-ray. Gives information about the size of the heart and signs of congestion in the lungs.
Further tests. An exercise test, an echocardiogram from the oesophagus or a cardiac MRI may be asked for if needed. These are not required in every patient.

Taking any earlier echocardiogram reports and a list of the medicines you use to the appointment is valuable, because it allows a comparison: how fast a valve is changing matters as much as the degree it is at today.

Does a Murmur Need Treatment?

The murmur itself is not treated; its cause is treated, if it has one.

An innocent murmur has no treatment and needs none. Where a murmur is due to a high-flow state the cause is corrected: anaemia is treated, the thyroid is settled, and a murmur heard in pregnancy usually disappears on its own after delivery.

Where a valve condition is found, the decision is made according to its degree and your symptoms. In mild and moderate valve disease the approach is most often follow-up with an echocardiogram at set intervals; medicines are used to manage symptoms and the conditions that go with them, such as blood pressure, rhythm disturbance and heart failure.

To be honest about it, medicines do not open a narrowed valve or stop a leaking one from leaking. When a procedure on the valve itself becomes necessary, catheter methods or surgery come into question. Which one suits you is decided by assessing the structure of your valve, your age, your other conditions and your symptoms together.

Murmurs in Children Are a Separate Subject

Murmurs are commonly heard in children and most of them are innocent. But assessing a child’s heart, and diagnosing and following congenital heart conditions, belongs to paediatric cardiology.

The information on this page is written for adults. If a murmur has been heard in your child, you should see a paediatric cardiologist.

Assessment of Murmurs and Heart Valves in Antalya

Prof. Dr. Umuttan Doğan is a cardiologist working in interventional cardiology and electrophysiology. Catheter procedures for valve conditions are carried out in the catheter laboratory at Antalya American Hospital.

If a murmur was heard at your examination, you can be seen at the clinic in Konyaaltı with any echocardiogram report and blood results you have. You will find his background and contact details on their own pages.

Frequently Asked Questions

I was told a heart murmur was heard — is it dangerous?

A murmur is an examination finding, not a diagnosis. In adults a good proportion of them are innocent murmurs, or are due to a correctable cause such as anaemia, pregnancy, fever or an overactive thyroid. Whether it points to a valve condition is established with an echocardiogram; if breathlessness, fainting or chest pain goes with it, the assessment should not be delayed.

How is an innocent murmur told apart from one due to a condition?

On examination, which phase the sound is heard in, where it is clearest and whether it changes with position give the first clues. A diastolic murmur is not regarded as innocent. But the definite distinction is not made by listening; it is made with an echocardiogram, and a murmur is not called innocent before the structure of the valves and the heart’s pump function have been seen.

My report says “grade 2/6 systolic murmur” — what does that mean?

It describes the loudness of the sound the doctor heard on a six-step scale, where 1/6 is the faintest and the upper steps are more obvious sounds. “Systolic” says the sound was heard in the heart’s contraction phase. The grade describes loudness, not the seriousness of the condition, which is why a low-grade murmur is also assessed with an echocardiogram.

Which tests are asked for when a murmur is heard?

The test at the centre is the echocardiogram; it shows the structure of the valves, the degree of any narrowing or leak and the heart’s pump function. An ECG, a blood count and thyroid tests go with it, and a chest X-ray if needed. An exercise test, an echocardiogram from the oesophagus or a cardiac MRI are needed only in particular situations.

Will a murmur go away in time, and are medicines needed?

Murmurs due to a high-flow state can disappear once the cause is corrected, and one heard in pregnancy usually goes after delivery. An innocent murmur needs no medicines. Where there is a valve condition the murmur does not go on its own, and medicines do not correct the valve itself; in mild and moderate degrees the approach is follow-up with an echocardiogram at set intervals.

The information on this page is for general guidance and does not replace a consultation. Decisions about diagnosis and treatment are made by your doctor after assessing your own situation.