Silent giant left atrium. A case report.

A sixty-two-year-old white woman with a 14.5 cm (145 mm) silent giant left atrial enlargement secondary probably to rheumatic heart disease is presented. Aside from mild progressive shortness of breath during the past year, the patient had been asymptomatic all her life. Her clinical picture was manifested for the first time by syncope secondary to slow atrial fibrillation, for which a permanent pacemaker was required. The correct diagnosis of the enlarged chamber was not possible through the routine chest roentgenogram. In this case, the echocardiogram, nuclear angiogram, and computed tomography were the pertinent studies needed to reach the diagnosis.