Left atrial ball thrombus.

The existence of a freely-floating thrombus in the left auricle is a rare finding in mitral pathology. Diagnosis by two-dimensional echocardiography has been described by various authors (1, 2, 3). In our case echocardiographic diagnosis of auricular thrombus was not possible at the beginning, given the bad ultrasonic window. Only when the thrombus floated freely in the left auricle it was detected in the region of the mitral valve, in spite of the bad ultrasound window.