Abstract
Giant left atrium is most commonly associated with rheumatic mitral valve disease, causing a series of cardiac and extracardiac complications. Cardiac complications are often reported, such as atrial fibrillation, decreased cardiac output, and atrial thrombus formation. Extracardiac complications are rarely described in the literature. We report an unusual case of a 55-year-old woman who was diagnosed with rheumatic heart disease 20 years earlier. Her chief complaints were episodes of chest tightness and difficulty breathing, which she had for more than 30 years. Echocardiography showed severe mitral stenosis with severe mitral insufficiency. Contrast-enhanced chest CT showed that the left thoracic cavity was occupied by a giant left atrium. The left main bronchus was compressed, and the left lung showed complete consolidation without pulmonary function.