Heart murmur

The heart murmur is an unusual sound that can be heard when listening with the stethoscope in addition to the normal heart sounds.
A linear blood stream is quiet, with restless blood flow this noise arises.


How does the heart work?

The heart consists of 4 chambers: 2 atria and 2 ventricles.

  • The atrium expands to suck blood from the lungs (left atrium) or from the tissue (right atrium), this phase becomes atrial diastole
  • Meanwhile, the ventricles pump the blood into the aorta (left ventricle) to the internal organs and into the pulmonary vein (right ventricle), this phase becomes ventricular systole
  • After that, the atrium pumps the blood to the ventricle of the same side (atrial systole).
  • At the same time, the ventricles expand to absorb the blood coming from the atria (ventricular diastole).

The heart normally produces two sounds: the first heart tone is a low-frequency, dull tone that occurs through the valve closure of the mitral and tricuspid valves; the second heart tone is a higher-frequency, brighter tone caused by the aortic and pulmonary valves. These two tones follow one another and should not be interrupted by any other tones. The heart murmur is a whistling or whistling that occurs together with the 1st and 2nd heart tone


  • Heart valve insufficiency = the heart valve does not close well and allows the blood to flow back.
  • Heart valve prolapse = a lobe of the heart valve protrudes in the opposite direction of blood flow, causing blood to flow back.
  • Heart valve stenosis = a narrowing of the heart valve.
  • Ventricular septal defect = part of the blood flows from the left ventricle to the right.

Classification of heart murmurs

Type of heart murmur by time

Depending on the time of occurrence and the form (or variation of intensity), the doctor can diagnose the particular heart condition. During auscultation, depending on the point at which the heart murmur is audible, one can understand from which heart valve the problem originates.

Systolic heart murmur (during systole of the ventricles)

May be normal or pathological.

Medium systolic outflow heart murmur – begins after the first heart tone and ends before the second.
This noise is caused by the flow of blood through the pocket flaps (anterograde, i.e. forward).
It occurs when the ventricle pumps the blood and ends with the blood flow stopping.
At the beginning, the heart murmur in relation to S1 is delayed. This period is called isovolumetric contraction and corresponds to the time it takes for the ventricle to build up pressure that exceeds the pressure of the aorta.
At this point, the aortic valve is opened by the blood pressure in the ventricle and an “outflow click” is heard.

The configuration of this heart murmur corresponds to a diamond or rhombus (crescendo-decrescendo), as it intensifies during the contraction of the ventricle and decreases during relaxation.


  1. Aortic or pulmonary stenosis, in an aortic stenosis, the heart murmur is also heard at the level of the carotid arteries.
  2. Dilated aortic or pulmonary artery.
  3. Increased flow at a normal heart valve (due to anemia, hyperthyroidism, etc.).

Late systolic heart murmur (in the final phase of systole) – It begins between the onset and middle of systole with a click corresponding to the tension of the chordae tendineae of the heart valve.
A feature of this heart murmur is that its intensity is constant until the end of systole.

Reasons for this can be:

  1. Prolapse of the mitral or tricuspid valve
  2. Dysfunction of papillary muscle

In a mitral valve prolapse, the click is not heard immediately after S1, but approximately in the middle of the systole.
This sound corresponds to the maximum tension of the chordae tendineae, i.e. the time at which the prolapse of the heart valve stops.

For the diagnosis of prolapse, the following features are important:

  • The click in the middle of systole
  • The constant intensity

Holosystolic or pansystolic heart murmur (from the beginning to the end of systole) – starts at S1 and extends to S2.

The cause can be:

  1. Mitral valve or tricuspid regurgitation
  2. Interventricular or interatrial septal defect

When the mitral valve is normal, the pressure in the left ventricle causes the heart valve to close because it is higher than the pressure in the atrium.

In mitral regurgitation (with prolapse), the blood returns to the left atrium throughout the contraction of the ventricle, causing a constant heart murmur.

As the ventricle pushes blood into the atrium, it expands over time to absorb the returning blood.
As a result, the atrium can absorb more blood at the same blood pressure.
This heart murmur radiates into the armpit.

Diastolic heart murmur (during diastole of the ventricles)

This disorder is always pathological.

Types of diastolic heart murmurs

Protodiastolic – Starts together with S2, which corresponds to the closure of the pocket valves (aortic and pulmonary valves) and ends before S1.
Reasons for this can be:

  • Pulmonary and aortic valve regurgitation
  • Enlargement of the heart valve ring

Since the aortic valve does not close completely, the blood returns to the ventricle during diastole, where blood pressure is lower.

Ventricular pressure increases rapidly as the volume of blood it contains increases because:

  1. The atrium pumps blood into the ventricle
  2. A small flow of blood leaks from the aorta

Therefore, the heart murmur is stronger at the beginning and then becomes weaker: descending.
Aortic regurgitation is perceived along the left sternal margin, while pulmonary valve regurgitation is noticeable at the upper right edge of the sternum.

Diastolic rolling – starts after S2 (closing the aortic valve) and ends at S1.

In the first phase of diastole, the ventricle fills very quickly, as the pressure difference between the atrium and ventricle is greater (stronger heart murmur).
You hear a click (opening sound) because the stenotic flap is stiff, and finally you hear the lock when the opening reaches its limit.
At the end of diastole, the atrium contracts to pump blood into the ventricle. The result is an accentuation of the heart murmur in the presystolic phase (presystolic amplification).
The cause is mitral or tricuspid valve stenosis.
Diastolic rolling is heard in the mitral area.

Causes of physiological heart murmur

The physiological heart murmur is caused by blood flowing faster than normal through the heart and coronary arteries (ejection sound of the heart); It can be caused by:

  • physical activity
  • Age
  • Fever
  • Anaemia
  • Hyperthyroidism (hyperthyroidism)
  • infarction (one of the main causes in adults),
  • trauma to the thorax,
  • Tachycardia
  • Pregnancy.

Abnormal or pathological heart murmur

The abnormal or pathological heart murmur can be caused by:

  • Congenital (since birth) defects in the heart. A child can be born with valvular defects and defective blood vessels. Other abnormalities affect septal problems.
  • Infections. Pathogenic germs damage the heart valves and other structures of the organ.
  • Rheumatic feverRheumatic fever is a serious disease caused by bacteria, especially streptococci. It causes:
    • Sore throat
    • Fever
    • Scarlet fever.

    The heart structures can be permanently damaged.

  • endocarditisEndocarditis is an inflammation of the inner lining of the heart and heart valves caused by bacteria and other microorganisms. The infection spreads through the blood to the other parts of the body. This condition is mainly diagnosed in people with genetic abnormalities of the heart. Endocarditis must be treated immediately, otherwise the heart valves will be damaged.
  • Calcification and heart valve stenosis. Calcification leads to hardening or thickening of the heart valves (aortic stenosis or mitral stenosis) and can cause heart murmurs.
  • Hyperthyroidism– Overactive thyroid gland and thyrotoxicosis.
  • Mitral valve prolapseThe heart valve does not close correctly. When the left ventricle contracts, the “sails” of the valve turn upwards into the atrium.

Symptoms of heart murmurs

Some heart murmurs indicate a heart problem and possible symptoms include:

  • blue discoloration (cyanosis) of the fingers and inside of the mouth,
  • rapid breathing,
  • excessive sweating,
  • chest pain,
  • Vertigo
  • Shortness of breath
  • Fatigue
  • Faint
  • Nausea
  • swelling of the legs and feet,
  • rapid weight gain,
  • chronic cough,
  • enlarged liver,
  • enlarged cervical veins.

Diagnosis of heart murmur

The cardiologist is able to diagnose a heart murmur through auscultation (eavesdropping) of the heart. It may also order investigations; The most suitable are:

  • echocardiogram and Doppler sonography,
  • chest X-ray,
  • Electrocardiogram (ECG).

To determine whether the heart murmur is pathological, the Levine classification is applied, which divides the heart murmur into 6 degrees:

  • 1/6 very quiet, only audible in certain positions,
  • 2/6 quiet,
  • 3/6 moderately loud,
  • 4/6 very noisy,
  • 5/6 very intense,
  • 6/6 also audible when the stethoscope is slightly raised from the chest wall.

Therapy for heart murmur

Benign heart murmurs do not require treatment because the heart is healthy.

Abnormal heart murmurs are treated along with the heart disease they cause. These sounds are treated with pharmaceuticals and surgically.
Medications prescribed by the doctor include:

  • Diuretics
  • Antibiotics
  • Anti-inflammatories.

Surgery serves to replace a defective heart valve or corrects congenital anomalies or septal defects.

Sport and prevention

Preventing a heart murmur is important.

  • Follow a low-fat diet to reduce cholesterol.
  • Quit smoking, as smoking increases cardiovascular risk.
  • Avoid high blood pressure.

In the case of a physiological or harmless heart murmur, the doctor recommends that a young person engage in their favorite sport to improve cardiovascular health.
With a pathological or malignant heart murmur, sports can also be dangerous for athletes.

Heart murmur in newborns

About 85% of children have a heart murmur in the first 24 hours after birth, but that disappears in the following 48 hours. These sounds are caused by the volume of blood vessels: newborns have very small arteries, veins and capillaries.
After birth, blood flow to the lungs occurs (for the first time), causing “turbulence”.
A heart murmur can:

  • be harmless, or
  • pathological: symptom of a heart defect.

There are no specific symptoms of harmless (physiological or functional) heart murmur in infants. Only if the cause is a congenital defect, one can observe serious symptoms. In 90% of cases of heart murmurs in newborns, it is a functional type.

Benign heart murmurs: This type of sound is called a functional heart murmur, it is a sign of a healthy heart and is created by the sound of blood passing through the heart. It does not require therapy. It is very common in children.

Heart murmur due to congenital heart defect: It is the result of an abnormality of the heart structure. The heart murmur is a consequence of structural problems of the heart, in this case the heart murmur is pathological.
These include:

  • Heart valve abnormality
  • Cardiomyopathy
  • Septal

Septal defects are caused by holes in the heart wall. The hole can cause extra blood flow.
Cardiomyopathy is a disorder of the heart muscle in which the heart muscles are thickened yet weakened. The result is an altered functioning of the heart.

If the doctor suspects that the heart murmur is caused by heart problems, further examinations may be carried out, such as:

  • Electrocardiogram
  • chest X-ray,
  • Echocardiogram.

In pregnancy, the health of the mother can adversely affect the health of the child. Does the mother suffer from:

  • Rubella
  • Diabetes

or has problems with alcohol abuse, increases the risk of pathological heart murmur in the child.

Therapy for heart murmurs in newborns
The treatment of heart murmur depends on the cause.
There is no need to worry about physiological or harmless heart murmurs, because they are not dangerous and do not need to be treated.
If the heart defect is congenital and diagnosed by laboratory tests, the newborn needs surgery.

A heart murmur in newborns is quite common and is not a serious health problem. Observe the parents symptoms, such as:

  • Anorexia
  • accelerated breathing,
  • growth retardation,
  • excessive sweating,
  • bluish lips and nails,

You should consult a pediatrician to clarify the cause of the heart murmur.

The cause may be a ductus botalli, which is a small hole that connects the pulmonary artery to the aorta and can cause problems in the heart.
This congenital defect is more common in premature infants (about 40%).
Among the heart murmurs in children, there is also the foramen ovale persistens, which is a small opening between the right and left atrium of the heart.

Heart murmur in children

Older children may have a heart murmur. Some children have very fine chest walls, in which case the heart murmurs become audible. This type of heart murmur is called a functional (or benign) heart murmur. Parents don’t have to worry about this noise.

  • In some cases, the heart murmur can be caused by stress, anemia, or fever.
  • Narrow blood vessels can also cause an abnormal noise.

If a strong noise is heard, further investigation may be required. X-rays are taken to reveal any heart defects.
An electrocardiogram confirms that the heartbeat is normal.

In the case of a benign heart murmur, no therapy is required.
There are very rare cases where the heart murmur can cause serious heart problems.
There are risks and complications among them, which can also lead to death.

As a rule, a benign heart murmur decreases over time.
The sounds become less audible as the thoracic wall increases in thickness.