Coconut atrium is the term coined for complete calcification of the left atrium in chronic rheumatic valvular heart disease . The stimulus for calcification could be the chronic inflammatory process of rheumatic fever as well as the strain due to atrial overload. Reduced left atrial compliance leads to elevation in pressures which gets transmitted to the pulmonary venous system, pulmonary arteries and sequentially to the right heart. Chest X-ray will show the calcified outline of the left atrium , which can be further confirmed by computerized tomographic (CT) scan.
Coconut atrium has also been called as ‘porcelain atrium’ akin to the ‘porcelain aorta’ . Presence of such extensive calcification is important in the setting of mitral valve surgery. Mitral valve replacement procedures and radiotherapy  can also predispose to calcification. Coconut left atrium has been described 23 years after mitral valve replacement for chronic mitral stenosis, in spite of normal prosthetic mitral valve function . The patient had exertional dyspnea and severe pulmonary hypertension.
Coconut atrium can predispose to atrial fibrillation and systemic embolization . Another term applied to extensive left atrial calcification is mold-like calcification .
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