[Pulmonary thromboembolism with mobile thrombus in the right atrium. Presentation of a case diagnosed with bidimensional echocardiography and review of the literature].

A case is presented of a pulmonary thromboembolism secondary to detachment of an elongated and mobile thrombus in right atrium, identified by bidimensional echocardiography in a patient without previously identified cardiac pathology. The presence of pulmonary thromboembolism in this patient was confirmed by lung angiography. In-spite of anticoagulant treatment, the patient died four days later due to massive pulmonary embolism, before a surgery could be carried out, coinciding with the disappearance of the right atrium thrombus by bidimensional echocardiography. The echocardiographic characteristics of right atrium thromboembolisms are described as well as their differential diagnosis and the most appropriate therapeutic attitude in these cases based in a literature review.