Familial Atrial Myxoma

At a glance

Atrial myxoma is the most common primary heart tumor. It usually is nonmalignant and sporadic, but 10% are familial.

Synonyms

Atrial Myxoma; Intracardiac Myxoma.

Incidence

Cardiac myxomas account for 40 to 50% of primary cardiac tumors. They are solitary and pedunculated and usually involve only the left atrium in the nonfamilial form (90% of cases) and both sides of the heart in the familial form (10% of atrial myxomas). In the sporadic cases, the female-to-male ratio is 3:1, whereas both sexes are equally involved in the familial cases. The overall prevalence of primary cardiac tumors is approximately 0.02% (200 tumors per one million autopsies); approximately 37.5% of them are myxomas (75 cases of myxoma per one million autopsies).

Genetic inheritance

In cases of familial occurrence (10% of atrial myxomas), the transmission is autosomal dominant.

Pathophysiology

The tumor is benign but can be lethal if it obstructs a valve or causes major embolic events. It arises from the epithelium and acts as a space-occupying lesion. A left atrial lesion behaves as a mitral valve stenosis and leads to pulmonary edema, whereas a right atrial lesion acts as a tricuspid valve stenosis and manifests with dyspnea and hypoxemia. These tumors are friable, resulting in tumor embolism that occurs in approximately 30 to 40% of patients. Symptomatology depends on the location of the tumor (left or right atrium) and the presence of an intracardiac shunt.

Diagnosis

Confirmed by an echocardiogram in suspected cases. Cardiac tumors constitute only 0.2% of all tumors. Primary cardiac tumors occur infrequently with an incidence of 0.0017 to 0.19%, estimated on autopsies performed in nonselected populations. Left atrial myxomas are the most prevalent (75-80%) and right atrial are less common (10-18%). Surgical excision yields an excellent prognosis and recurrence rate of only 3% with a very low morbidity and mortality.

Clinical aspects

Symptoms are produced by mechanical interference with cardiac function or embolization. It seems this family condition involves younger patients with more frequent lesions on the right side of the heart and more recurrences over the years. Complications associated with the disease, such as vascular aneurysms, are not more common in the familial cases. The classic triad of symptoms, of which at least one is present, comprises obstructive traits including dyspnea and syncope, constitutional symptoms such as fever and anorexia, and thromboembolic events.

Precautions before anesthesia

An echocardiogram and ECG are needed preoperatively to document the extent and number of lesions and their effect on the hemodynamics of the heart. An angiogram should be part of the workup to rule out the presence of vascular aneurysms in the cerebral, coronary, and ...