Atrial Myxoma Clinical Presentation

Symptoms range from nonspecific and constitutional to sudden cardiac death. In about 20% of cases, myxoma may be asymptomatic and discovered as an incidental finding. Signs and symptoms of mitral stenosis, endocarditis, mitral regurgitation, and collagen vascular disease can simulate those of atrial myxoma. A high index of suspicion aids in diagnosis.

• Symptoms of left-sided heart failure

  • Dyspnea on exertion (75%) that may progress to orthopnea, paroxysmal nocturnal dyspnea, and pulmonary edema is observed.
  • Symptoms are caused by obstruction at the mitral valve orifice. Valve damage may result in mitral regurgitation.
• Symptoms of right-sided heart failure

  • Patients experience fatigue and peripheral edema.
  • Abdominal distension due to ascites is rare; however, it is more common in slowly growing right-sided tumors.
  • These symptoms are also observed in the later stage of progressive heart failure associated with left atrial myxomas.
• Severe dizziness/syncope

  • This is experienced by approximately 20% of patients.
  • The most frequent cause in patients with left atrial myxomas is obstruction of the mitral valve.
  • Symptoms may change as the patient changes positions.
• Symptoms related to embolization

  • Systemic or pulmonary embolization may occur from left- or right-sided tumors.
  • Left-sided symptoms are produced from the infarction or hemorrhage of viscera.
  • Embolization to the central nervous system may result in transient ischemic attack, stroke, or seizure. In an analysis of 113 cases of atrial myxoma with neurologic presentation, 83% of patients presented with ischemic stroke, most often in multiple sites (43%). Twelve percent of patients presented with seizures. In a retrospective review of 74 patients with atrial myxoma, 12% had neurologic manifestations.^[9] Cerebral infarction was present in 89% of the cases and most myxomas (89%) demonstrated a mobile component on transesophageal echocardiography. Other complications include myxoma-induced cerebral aneurysm and myxomatous metastasis that can mimic vasculitis or endocarditis.
  • Involvement of the retinal arteries may result in vision loss.
  • Systemic embolization that causes occlusion of any artery, including coronary, aortic, renal, visceral, or peripheral, may result in infarction or ischemia of the corresponding organ.
  • On the right side, embolization results in pulmonary embolism and infarction.
  • Multiple, recurrent small emboli may result in pulmonary hypertension and cor pulmonale.
  • Presence of an intracardiac shunt (atrial septal defect or patent foramen ovale) may result in a paradoxical embolism.
• Constitutional symptoms that include fever, weight loss, arthralgias, and Raynaud phenomenon are observed in 50% of patients. These symptoms may be related to overproduction of interleukin-6.
• Hemoptysis due to pulmonary edema or infarction is observed in up to 15% of patients.
• Chest pain is infrequent. If it occurs, it may be due to coronary embolization.
• One recent case report of 5-year history of visual loss, vertigo, ataxia, tinnitus, and bone lesions that resolved after diagnosis and resection of the atrial myxoma has raised a possibility of it causing a paraneoplastic syndrome.^[10]
• Atrial myxoma can get infected when vegetations may be seen attached to its surface.^[11]

• Jugular venous pressure may be elevated, and a prominent A wave may be present.
• A loud S₁ is caused by a delay in mitral valve closure due to the prolapse of the tumor into the mitral valve orifice (mimicking mitral stenosis).
• P₂ may be delayed. Its intensity may be normal or increased, depending on the presence of pulmonary hypertension.
• In many cases, an early diastolic sound, called a tumor plop, is heard. This sound is produced by the impact of the tumor against the endocardial wall or when its excursion is halted.
• An S₃ or S₄ may be audible.
• A diastolic atrial rumble may be heard if the tumor is obstructing the mitral valve.
• If there is valve damage from the tumor, mitral regurgitation may cause a systolic murmur at the apex.
• A right atrial tumor may cause a diastolic rumble or holosystolic murmur due to tricuspid regurgitation.
• General examination may reveal fever, cyanosis, digital clubbing, rash, or petechiae.
• Patients with familial myxoma may have a variety of features called syndrome myxoma or Carney syndrome^[12] , as follows:

  • Myxomas in breast, skin, thyroid gland, or neural tissue
  • Spotty pigmentation such as lentigines (ie, flat brown discoloration of skin), pigmented nevi, or both
  • Endocrine hyperactivity such as Cushing syndrome
  • Multiple cerebral fusiform aneurysms may be seen in patients with Carney syndrome.^[13]
• Other described syndromes associated with atrial myxomas include the following:

  • NAME syndrome features nevi, atrial myxoma, myxoid neurofibroma, and ephelides (ie, freckles [tanned macules found on the skin]).
  • LAMB syndrome features lentigines, atrial myxoma, and blue nevi.

• Most cases of atrial myxoma are sporadic, and the exact etiology is unknown.
• Familial atrial myxomas have an autosomal dominant transmission.
• Carney syndrome is genetically heterogenous and is caused by a defect in more than one gene. It is estimated to account for 7% of all atrial myxomas without any predilection for age or sex. Abnormalities in the short arm of chromosome 2 (Carney) and chromosome 12 (Ki-ras oncogene) have been described. In a recent case report, a frame-shift mutation was found in exon 2 in the causative gene of Carney complex, protein kinase A regulatory subunit 1 alpha (PRKAR1A).^[14]