Embolism refers to blockage of an artery, whereas infarction denotes necrosis of the pulmonary tissue resulting from inadequate blood supply. Embolism is associated with a minimal pulmonary physical finding and very few roentgenographic findings other than the loss of vascular pattern in the region involved. Embolism and infarction occur in different clinical settings, although the two may coexist.
A suggestion is raised that a relatively small pulmonary embolism may cause sufficient arteriospasm to give rise to anxiety and dyspnea, thus mimicking a larger occlusion. Embolism of one of the main pulmonary arteries is less common than multiple lobar or smaller occlusions. When one of the main pulmonary arteries contains a large embolus, usually there are emboli in the other lung and it is the latter episode which results in death.
One might argue that this small monograph could easily have been condensed into a rather large single article in a