Electrocardiogram, chest X-ray, and transthoracic echocardiogram. (A) Electrocardiogram showing sinus rhythm with P wave negative in V1 suggestive of left atrium Dilatation (black arrows). (B) Chest X-ray showing Grade III cardiomegaly, and double contour image (arrow) suggestive of left atrium dilatation. (C) Transthoracic echocardiogram. C1: long parasternal axis view showing a giant mass (circle) in the whole left atrium. C2 and C3: apical four-chamber view showing a giant mass obstructing all the left ventricle inflow tract and causing a pseudo-mitral stenosis.