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CASE OF THE MONTH

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Patrick E. Scanlon, PA-C; David Schifter, MD, FACC; Terrence J. Sacchi, MD, FACC; Joseph A. Puma, DO, FACC

CASE

Mrs. G. is a 57-year-old woman who presented to a cardiologist with several months of generalized edema, fatigue, and weight gain. She denied shortness of breath, chest pain, syncope, dizziness, fever, or palpitations. In addition to hypertension that is controlled with low-dose ß-blocker therapy, Mrs. G. has type 2 diabetes, osteoarthritis, and benign fibrocystic changes of the right breast. She is allergic to morphine and codeine. She denied alcohol, tobacco, or illicit drug use.

Exam The patient's BP was 132/76 mm Hg; pulse, 88 beats per minute; respirations, 20 breaths per minute; and temperature, 98.8°F. The physical exam was unremarkable except for a mild systolic murmur at the apex. The results of routine lab studies—including a CBC, basic metabolic profile, thyroid panel, urinalysis, and erythrocyte sedimentation rate—were within normal ranges.

Imaging Two-dimensional echocardiography revealed an undefined echo-dense mass in the left atrium. The structure and size of the heart were normal, and the left ventricular ejection fraction was 75%. Transesophageal echocardiography revealed a long, narrow mass in the left atrium; the mass was attached to the superior portion of the atrial septum and extended almost to the mitral valve, but it did not involve the pulmonary vein (see Figure 1). The widest point of the mass was approximately 0.5 cm.

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A cardiothoracic surgical referral resulted in surgery 2 days later to resect the mass. The pathology report revealed an atrial myxoma approximately 1.2 x 0.8 x 0.3 cm in size.

DISCUSSION

Atrial myxoma is a common primary cardiac tumor and is usually located in the left atrium. The cause is unknown, although 10% of cases are familial. The mean age of patients affected is 56 years; approximately 70% are women.

Symptoms tend to be nonspecific and related to mechanical interference with cardiac function. Obstruction commonly occurs at the orifice of the mitral valve, causing symptoms of left-sided heart failure, including dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema. (Fatigue and peripheral edema are associated with right-sided heart failure, which develops after left-sided heart failure.) Approximately 20% of patients will experience severe dizziness and syncope, typically caused by obstruction of the mitral valve. Other symptoms include weight loss, arthralgia, fever, and Raynaud's sign. The differential diagnosis includes infective endocarditis, collagen vascular disease, pulmonary embolism, mitral or tricuspid valve stenosis and regurgitation, pulmonary hypertension, and carcinoid heart disease.

Laboratory data are usually nondiagnostic and nonspecific. In severe disease, a chest film will show an abnormal cardiac silhouette and possible pulmonary edema. Transesophageal echocardiography is the most sensitive diagnostic study and can best assess tumor location, size, point of attachment, and motion. Cardiac catheterization may be warranted when noninvasive modalities are inconclusive.

Treatment and follow-up Surgical resection is the treatment of choice and is associated with a low postoperative mortality rate of approximately 2.2%. Although recurrence is rare, tumors that reappear typically do so within 4 years of resection. Follow-up includes two-dimensional echocardiography every 6 months for about 5 years. There is currently no medical treatment for atrial myxoma, although complications, such as heart failure, should be managed appropriately.

SUGGESTED READING

Ha JW, Kang WC, Chung N, et al. Echocardiographic and morphologic characteristics of left atrial myxoma and their relation to systemic embolism. Am J Cardiol. 1999;83:1579-1582,A8.

Reynen K. Frequency of primary tumors of the heart. Am J Cardiol. 1996;77:107.

Roberts WC. Primary and secondary neoplasms of the heart. Am J Cardiol. 1997;80:671-682.

Sawaya JI, Dakik HA. Angiographic visualization of an atrial myxoma. N Engl J Med. 2000;342:294,295.

Topol EJ. Specific benign primary cardiac neoplasms. In: Topol EJ, Califf R, Isner JM, et al, eds. Textbook of Cardiovascular Medicine. Philadelphia, Pa: Lippincott-Raven; 1998:975-977.

The authors practice at New York Methodist Hospital, Brooklyn, NY. They have indicated no relationships to disclose relating to the content of this article. Mr. Fogg is Assistant Professor in and Program Director of the Physician Assistant Program at the College of Health Professions, University of New England, Portland, Me.