An atrial myxoma is a noncancerous tumor in the upper left or right side of the heart. It grows on the wall (atrial septum) that separates the two sides of the heart.
Causes, incidence, and risk factors
A myxoma is a primary heart (cardiac) tumor. This means that the tumor started within the heart. Most heart tumors start somewhere else.
Primary cardiac tumors are rare. Myxomas are the most common type of these rare tumors. About 75% of myxomas occur in the left atrium of the heart, usually beginning in the wall that divides the two upper chambers of the heart. The rest are in the right atrium. Right atrial myxomas are sometimes associated with tricuspid stenosis and atrial fibrillation.
Myxomas are more common in women. About 10% of myxomas are passed down through families (inherited). Such tumors are called familial myxomas. They tend to occur in more than one part of the heart at a time, and often cause symptoms at a younger age than other myxomas.
Symptoms may occur at any time, but most often they accompany a change of body position. Symptoms may include:
- Breathing difficulty when lying flat
- Breathing difficulty when asleep
- Chest pain or tightness
- Sensation of feeling your heart beat (palpitations)
- Shortness of breath with activity
The symptoms and signs of left atrial myxomas often mimic mitral stenosis.
General symptoms may also be present, such as:
- Blueness of skin, especially the fingers (Raynaud's phenomenon)
- Curvature of nails accompanied with soft tissue enlargement (clubbing) of the fingers
- Fingers that change color upon pressure or with cold or stress
- General discomfort (malaise)
- Involuntary weight loss
- Joint pain
- Swelling - any part of the body
These general symptoms may also mimic those of infective endocarditis.
Signs and tests
The health care provider will listen to the heart with stethoscope. A "tumor plop" (a sound related to movement of the tumor), abnormal heart sounds, or murmur may be heard. These sounds may change when the patient changes position.
Right atrial myxomas rarely produce symptoms until they have grown to be at least 13 cm (about 5 inches) wide.
Imaging tests may include:
- Chest x-ray
- CT scan of chest
- Doppler study
- Heart MRI
- Left heart angiography
- Right heart angiography
The tumor must be surgically removed. Some patients will also need their mitral valve replaced. This can be done during the same surgery.
Myxomas may come back if surgery did not remove all of the tumor cells.
Although a myxoma is not cancer, complications are common. Untreated, a myxoma can lead to an embolism (tumor cells breaking off and traveling with the bloodstream), which can block blood flow or cause the myxoma to grow in another part of the body. Myxoma fragments can move to the brain, eye, or limbs.
If the tumor grows inside the heart, it can block blood flow through the mitral valve and cause symptoms of mitral stenosis. This may require emergency surgery to prevent sudden death.
Calling your health care provider
Tell your health care provider if there is any family history of myxomas or if you have symptoms of atrial myxoma.
Reviewed By: Issam Mikati, MD, Associate Professor of Medicine, Feinberg School of Medicine, Director, Northwestern Clinic Echocardiography Lab, Northwestern University, Chicago, IL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.