Giant cardiac structure in thoracic cavity.

A 52-year-old male patient with a history of mitral valve replacement due to rheumatic valve disease was admitted to our clinic with shortness of breath. Heart sounds revealed metallic 1st heart sound and normal 2nd heart sound without any murmur. Breath sounds were not heard over the lower and middle zones of the right lung with dullness on percussion. Telecardiography was remarkable with a cardiac silhouette filling almost all portions of middle and lower parts of thorax on the right side. He had also double contour shape in the cardiac silhouette, which is a sign of left atrial dilatation (Fig. 1). Transthoracic echocardiography demonstrated an ejection fraction of 38% and left ventricular enddiastolic diameter of 60 mm. The most important finding was in the left atrium. It had a dimension of 182x181 mm on apical four-chamber view (Fig. 2, Video 1. See corresponding video/movie images at www.anakarder.com). Functions of prosthetic mitral valve were normal. Ball-like mass image of the left atrium filling right hemithorax completely and left hemithorax partially showed an interesting image on telecardiography. In addition, left atrial dilatation was clearly visualized on the telecardiography. A giant left atrium is a rare and well-known entity associated with mitral valve disease. It can be misdiagnosed from telecardiography as a mass lesion or pleural or pericardial effusion especially in unstable patients. Pleurocentesis and biopsy can be dangerous. When such a cardiomegaly is detected in telecardiography, an appropriate differential diagnosis must be made by using modalities like echocardiography and thorax computed tomography.