Witnessed massive pulmonary thromboembolism and dynamic left ventricular outflow tract obstruction.

The authors describe a patient with a floating thrombus in the right heart that migrated into the pulmonary artery, causing on-site massive pulmonary thromboembolism during echocardiography and systolic anterior motion of the anterior mitral leaflet resulting in significant dynamic left ventricular outflow tract obstruction. Reduced pulmonary circulation due to pulmonary embolism and decreased systemic circulation associated with left ventricular outflow tract obstruction resulted in a fatal outcome.