An atrial myxoma is a rare tumor located in the upper chamber (atrium) of the heart, involving the connective tissue within the heart muscle. A myxoma is a benign (not cancerous) tumor, but it can have dangerous complications. It can cause blockage of blood flow, and it can metastisize (spread to other areas) if blood clots form, by attaching to the clot material. It is a primary tumor, which means that the tumor originates in the heart, instead of spreading from a tumor located elsewhere in the body.

Atrial myxomas can occur in the left or right atrium. Over 80% of myxomas are in the left atrium. Left atrial myxoma occurs in approximately 5 out of 1,000,000 people. Right atrial myxomas are very rare, occurring in about 1 out of 1,000,000 people. Myxomas are more common in women.

What causes atrial myxoma?

A family history of cardiac myxoma can mean your risk of developing the tumor are increased. A history of any of the following can increase the likelihood of a cardiac myxoma:

• tissue death in the bowel
• recent peripheral emboli
• recent pulmonary emboli
• recent systemic emboli
• mitral stenosis
• tricuspid stenosis (associated with right atrial myxomas only)
• atrial fibrillation (associated with right atrial myxomas only)

What are the symptoms of atrial myxoma?

Symptoms can include:

• chest pain or tightness
• swelling of the hands, feet, or any body part (edema)
• swelling of the abdomen
• prominent veins in the neck
• shortness of breath (dyspnea)
• dizziness
• fainting (syncope)
• sensation of feeling heart beat (palpitations)

How is atrial myxoma diagnosed?

Your doctor will perform a physical exam. Symptoms of atrial myxoma may mimic heart failure. Examination of the heart with a stethoscope may show "tumor plop" (a sound related to movement of the tumor) or other abnormal sounds. Neck veins may be enlarged.

An echocardiogram (cardiac ultrasound) is a very useful test in diagnosing atrial myxoma. Other helpful studies include cardiac MRI, cardiac catheterization and a CT scan of the chest.

How is atrial myxoma treated?

Open heart surgery is necessary to remove atrial myxomas. The tumor and the portion of the heart wall to which it is attached are removed. Atrial myxomas occasionally re-grow following surgery.