Teaching Case

Chronic mixed mitral valve disease.

This patient has a long standing history of mixed mitral valve disease with atrial fibrillation. Her past history includes rheumatic fever, mitral valvotomy 26 years ago and mitral valvuloplasty 8 years ago. Her symptoms of dyspnoea on moderate exertion and orthopnoea remain stable. On examination, she has pan systolic murmur and mid diastolic murmur. A PA chest radiograph and contrast enhanced mutidetector CT of the thorax were performed.

Left atrial calcification is the end result of extensive chronic rheumatoid heart disease. The patient is usually female and middle-aged with severe mitral valve disease. Mitral stenosis is usual, with some mitral regurgitation. Calcification of the left atrium is frequently associated with atrial fibrillation, long standing congestive cardiac failure, mural thrombus and embolization. Calcification has also been reported in some patients with chronic renal failure. Left atrial calcification appears as a thin curvilinear density tracing the outline of left atrium in part or completely. In the frontal projection, a round or oval shell of calcium 8-10cm in diameter is seen lying in the centre of cardiac silhouette, beneath the carina and main stem bronchi. In the lateral projection, a completely calcified wall appears as a c-shaped curvilinear density with opening of the c lying anteriorly in the region of mitral annulus. The valve may also be calcified. The septal surface of the atrium is usually free of calcium. The appendage alone may calcify, visible on the left border on the anterior view and the middle of the heart on the lateral view. Calcification rarely extends to pulmonary veins. Thrombus, often presents within a calcified left atrium, and may also calcify in thick laminated layers. Left atrial calcification must be differentiated from calcification occurring in cardiac valves, pericardium, coronary arteries, ventricular aneurysm or infarction, intracardiac tumours, mediastinal cysts, hilar nodes and costal cartilage. Recognition of atrial calcifications is essential for the management of patients, particularly when surgical intervention is contemplated.