Atrial myxoma - left

Alternative names
Tumor - heart; Cardiac tumor; Myxoma - atrial; Myxoma - heart tumor


A left atrial myxoma is a benign tumor located in the left upper chamber of the heart (atrium) on the wall that separates the left chamber from the right (the atrial septum). See also atrial myxoma - right.

Causes, incidence, and risk factors

A myxoma is a primary heart (cardiac) tumor. This means that the initial site of the growth was within the heart, which is uncommon with heart tumors. Most have spread from elsewhere in the body (metastasized).

Primary cardiac tumors are rare, but among them, myxomas are the most common. about 75% of myxomas occur in the left atrium, usually beginning in the wall that divides the upper chambers of the heart (atrial septum) and growing into the atrium. However, right atrial myxoma may also occur.

Myxomas are more common in women.

Approximately 10% of all myxomas are familial, which means that they were genetically inherited. Familial myxomas tend to produce symptoms at a younger age than non-familial tumors and are often multiple, that is, are present in more than one site within the heart and can include the ventricles (lower heart chambers).


Symptoms may occur at any time, but most often they accompany a change of body position. Symptoms may include:

  • Shortness of breath with activity  
  • Breathing difficulty when lying flat  
  • Breathing difficulty when asleep  
  • Dizziness  
  • Fainting  
  • Sensation of feeling your heart beat (palpitations)  
  • Chest pain or tightness

The symptoms and signs of left atrial myxomas often mimic mitral stenosis.

General symptoms may also be present, such as:

  • Cough  
  • Fever  
  • Involuntary weight loss  
  • General discomfort (malaise)  
  • Joint pain  
  • Blueness of skin, especially the fingers (Raynaud’s phenomenon)  
  • Fingers that change color upon pressure or with cold or stress  
  • Curvature of nails accompanied with soft tissue enlargement (clubbing) of the fingers  
  • Swelling - any part of the body

These general symptoms may also mimic those of infective endocarditis.

Signs and tests

Listening to the heart with a stethoscope, the doctor may hear a “tumor plop” (a sound related to movement of the tumor), abnormal heart sounds, or murmurs. These findings may change when the patient changes position.

The first diagnostic test is usually an echocardiogram (a test based on ultrasound waves to view the heart), often accompanied with a Doppler study. The echocardiogram allows visualization of the myxoma, cardiac valves and heart structure. Other tests include:

  • Chest X-ray  
  • CT scan of chest  
  • Heart MRI  
  • Left heart angiography  
  • Right heart angiography

An ECG may demonstrate atrial fibrillation.

Laboratory tests which may be altered include:

  • A complete blood count (CBC), which may show anemia, decreased platelet count, or elevated white blood cell count (WBC).  
  • Elevated ESR (erythrocyte sedimentation rate)  
  • Elevated interleukin-6 (IL-6)  
  • Altered levels of proteins, such as protein C and gammaglobulins.


The only effective treatment is surgical excision (removal) of the tumor. During the same procedure, some patients will also need to have their mitral valve replaced.

Myxomas may recur if the surgical removal was incomplete.

Expectations (prognosis)

The probable outcome is poor without treatment. Although a myxoma is a benign tumor, complications are common.

One complication of untreated myxoma is embolization (tumor cells breaking off and traveling with the bloodstream), which can obstruct a blood vessel or plant a myxoma in another part of the body where it can cause symptoms. Myxoma fragments can embolize to the brain, eye, or limbs.

Another complication is the local growth of the tumor, which can obstruct blood flow through the mitral heart valve and produce clinical symptoms of mitral stenosis.
The outlook for someone who had a left atrial myxoma that has been surgically removed is good; and patients usually remain symptom-free and have a normal lifespan.


  • Arrhythmias  
  • Pulmonary edema  
  • Peripheralemboli  
  • Spread (metastasis) of the tumor  
  • Local growth of the tumor, with obstruction of the mitral heart valve and symptoms of mitral stenosis; this may require emergency surgery to prevent sudden death

Calling your health care provider

Call your health care provider if symptoms indicate you may have an atrial myxoma.


Awareness of the disorder can make early detection and treatment possible.

When myxoma is confirmed in a patient, the patient’s relatives might undergo screening to rule out the familial form of the disorder.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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