Right ventricular outflow obstruction from thrombus with small peripheral pulmonary emboli

A patient is described with clinical features of massive pulmonary embolism and a normal pulmonary angiogram. At necropsy, a large thrombus obstructed right ventricular outflow. A right atrial or right ventricular angiogram is suggested in patients suspected of having pulmonary embolism when a pulmonary angiogram shows the pulmonary trunk and main right and left pulmonary arteries to be normal.