Makindo Medical Notes.com

Related Subjects: |Cardioembolic stroke

About

• Incidence of atrial myxomas found at autopsy is 0.03%
• Rare Cardiac Tumour first described in 1845
• Benign tumour usually in the left (or right) atrium
• Usually from left atrial septum near fossa ovalis

Genetics

• May occur as part of a NAME or LAMB syndromes
• Rarely familial autosomal dominant

Aetiology/Pathology

• Aetiology generally unknown. Single pedunculated lesion several cms in diameter L > R 4:1. Stellate multipotential mesenchymal cells and mixed connective tissue cells. These cells can differentiate into endothelial tissue. Pedicle allows movement of the tumour mass. Can block mitral valve
• Constitutional symptoms may be due to interleukin-6 by the myxoma. Normalization of high serum levels of interleukin-6 after tumour resection is often accompanied by resolution of these symptoms
• Symptoms seem to correlate with the size of the tumour as well as its mobility

Clinical and Aetiology

• Embolization: 35% have evidence of embolisation mostly to the brain. Emboli may be Tumour fragments or thrombus or even a shower of fragments and so not prevented by anticoagulation which may just encourage CNS haemorrhage
• Constitutional symptoms: fever (PUO), weight loss, fatigue, myalgia and arthralgia. Laboratory abnormalities such as anaemia, elevated sedimentation rate, elevated C-reactive protein, thrombocytosis or thrombocytopenia, elevated serum globulins, antinuclear antibodies, and rheumatoid factor may accompany the symptoms
• Cardiac and obstructive symptoms, Auscultation - tumour "plop" + diastolic murmur can mimic Mitral stenosis and heart failure. congestive heart failure, syncope, and, rarely, sudden death,

Obstructive features like MS, signs vary with posture. Occasionally, there is a low-pitched sound called tumour plop. There may be syncope or vertigo.

Images

Investigations

• Anaemia of chronic disease, Raised ESR, Rheumatoid factor, Raised CRP, ANA +ve
• PPE: Hypergammaglobulinaemia.
• Echocardiography: Diagnose with transthoracic echo which shows mass lesion in LA. However, TTE misses the diagnosis in 20% and transesophageal echocardiography has been reported as having 100% sensitivity for atrial myxoma> Look for mobility and a narrow stalk, often with echolucent areas representing haemorrhage or necrosis. Can be smooth globular surface to an irregular, friable surface,
• Cardiac MRI may also be useful in surgical planning. It has the advantage of more clearly delineating tumour size, attachment and mobility, as well as elucidating histological characteristics on gadolinium enhanced images. High spatial resolution and multiplane imaging combined with different acquisition patterns of cardiac MRI achieve a global view of the heart, which is useful for diagnosing cardiac myxoma
• Coronary angiography should be performed in all patients who present with atrial myxoma as the coronaries may perfuse the myxoma

Complications

• Arrhythmias, Sudden death
• Systemic emboli e.g. stroke
• Aneurysm formation
• Congestive cardiac failure

Management

• No medical therapy exists for atrial myxomas. Definitive treatment is surgical and, because of the risk of further embolization, should not be delayed.
• Surgical excision. Recurrence may occur: Given the risk of embolization, care is taken prior to cross-clamping the aorta to avoid excessive manipulation of the heart. Cold cardioplegia is attained, and cardiac bypass is utilized. Myxoma is excised along with a margin of endocardium. Primary closure may be possible but, otherwise, a graft is used to close the atrial septal defect created. Many surgeons explore all 4 chambers for evidence of other myxomas. In general, surgical management of myxoma gives good results
• Recurrent embolization is believed to be common when atrial myxomas are not excised. Systemic and haemodynamic symptoms are related to size, the longer the tumour is left untreated
• There is a 5% risk of recurrence so follow up needed. Most recurrences occur within the first 2 years, but they can be as prolonged as long as 12 years

References

• Atrial myxoma