Right atrial mural thrombus associated with pericarditis.

A 33-year-old man was hospitalized with right heart failure. He was diagnosed as having right atrial mural thrombus complicated with pericarditis on echocardiography, thoracic computed tomography, and cardiac catheterization. Pericardiectomy and thrombectomy with a partial resection of the right atrial wall were performed under extracorporeal circulation. It was suggested that the cause of right atrial thrombus was congestion, atrial fibrillation, and pericarditis. The cause of pericarditis could not be determined by pathologic examination and laboratory data. Surgical treatment should be performed as soon as possible to prevent pulmonary embolism.