Congenital aneurysm of the left atrium.

Isolated left atrial (LA) aneurysm is a rare condition, whereas LA aneurysm secondary to other causes is a fairly common condition. A case of large left atrial aneurysm presented with features of heart failure with cardiac arrhythmia and an abnormal cardiac silhouette on chest X-ray. A 14 years old girl presented with palpitation at rest, shortness of breath, productive cough and bilateral leg swelling for last 8 months. There was no history of chest pain, hemoptysis, syncope, prolonged fever, and rheumatic fever. She was mildly anemic, had raised JVP and mild bilateral pedal edema. There was left parasternal heave, soft S1, loud P2 and a pansystolic murmur of grade 3/6 over mitral area radiating to the left axilla. ECG showed multifocal atrial tachycardia (MAT), chest X-ray showed cardiomegaly with bulging of the left heart border with upper lobe diversion. Echo-Doppler study showed hugely dilated LA (115 mm in diameter), dilated left ventricle, Grade-2+ mitral regurgitation (MR), mild tricuspid regurgitation (TR) and mild pulmonary hypertension with normal appearing mitral, aortic and tricuspid and pulmonary valves. The patient was diagnosed as a case of congenital aneurysm of LA.