What is a Heart Murmur?

The heart makes sounds as it beats. These sounds occur as the heart valves open and close to allow blood to flow through the heart.

A heart murmur is an extra noise. It’s caused by blood not flowing smoothly through the heart. This is called turbulence. Heart murmurs can be innocent (harmless) or pathologic (caused by a heart problem).

What causes a heart murmur?

An innocent heart murmur is caused by mild turbulence in blood flow within the heart. Pathologic heart murmurs are often caused by structural heart defects. These might be:

  • Septal defects (holes in the dividing walls of the heart that allow blood to pass through)
  • Heart valve problems (valve has trouble opening or closing)
  • Artery-vein fistulas (abnormal connections between a blood vessel on the left side of the heart and a blood vessel on the right side of the heart)

How does a heart murmur feel?

Innocent heart murmurs cause no feelings or symptoms. Symptoms related to a pathologic heart murmur depend on the underlying cause of the murmur.

How is a heart murmur diagnosed?

The doctor or healthcare provider may detect a heart murmur during a physical exam. Heart noises are heard with a stethoscope. A heart murmur is classified by how loud it is, its location, when it occurs during the heart’s pumping cycle, and its sound qualities.

The following tests may be done:

  • Chest x-ray: This test takes a picture of the heart and lungs. The picture can show your heart’s size and shape. It can show whether there are problems in the heart or lungs.
  • Electrocardiography (ECG or EKG): During this test, the electrical activity of the heart is recorded to check for arrhythmias (abnormal heart rhythms) or problems with heart structure.
  • Echocardiography (echo): During this test, sound waves are used to create a picture of the heart. This test can show problems with heart structure or heart function. This includes showing how well the heart pumps, if the heart is enlarged or if there are any valve problems. 

How is a heart murmur treated?

An innocent heart murmur requires no treatment because it’s not a heart problem. Treatment for a pathologic murmur depends on the underlying cause. The cardiologist will evaluate your condition and discuss treatment options with you if needed.

What are the long-term concerns?

Most innocent murmurs go away by adolescence or adulthood. If pathologic heart murmurs aren’t diagnosed or treated, severe symptoms may result and cause serious health problems. These can include heart failure, arrhythmias or respiratory problems.