Transient obstruction of the mitral valve by a massive thrombus complicating percutaneous valvuloplasty

Percutaneous transseptal mitral valvuloplasty was attempted in a patient with severe rheumatic mitral stenosis. Introduction of the balloon into the left atrium resulted in thrombotic occlusion of the mitral valve. Circulatory arrest ensued. The thrombus was disrupted during cardiopulmonary resuscitation. Thrombolysis was administered and the patient recovered uneventfully.