A pulmonary embolism (PE) occurs when a blood clot—usually originating in the deep veins of the legs (Deep Vein Thrombosis or DVT)—travels through the bloodstream and lodges in the pulmonary arteries of the lungs. While many pulmonary embolisms can be managed using blood thinners or clot-dissolving medications (thrombolytics), massive or high-risk embolisms require immediate...