Thromboembolism in the right side of the heart.

Right-sided cardiac thromboemboli, or pulmonary emboli-in-transit, represent an unusual disease process with high morbidity and mortality. We present a detailed case report and a synopsis of our experience at the University of Mississippi Medical Center between 1990 and 1997 and review the current medical literature. These thrombi and emboli may largely be subdivided into type A--a mobile, serpiginous clot that is probably a mobilized deep vein thrombus--and type B--a rather immobile clot morphologically similar to left-sided heart thrombi that may represent intracardiac thrombosis. The mainstays of therapy include surgical embolectomy and thrombolysis, but there is no clear benefit of one over the other. Treatment should be individualized according to the clot's size and morphology, likelihood of preexisting pulmonary embolism, the patient's cardiopulmonary reserve, comorbid conditions, and local expertise with treatment modalities.