multiple bilateral pulmonary embolismmassive bilateral pulmonary embolismmassive saddle pulmonary embolismacute bilateral pulmonary embolismacute saddle pulmonary embolismsaddle block pulmonary embolismpulmonary embolism saddle clotsaddle pulmonarybilateral embolismsaddle embolism treatmentsaddle pulmonary embolism death ratesaddle pulmonary thromboembolism