It is not known with sufficient accuracy whether exertion, such as soldiers undergo in warfare, is accompanied by enlargement of the heart. The present study was undertaken to obtain information on this point. The examinations were made during May, 1919, of soldiers who had seen active service in the American Expeditionary Forces.1
The men were selected without regard to special criteria by line officers at one of the camps in the vicinity of New York.2 Infantrymen were chosen or men who had been subjected to an equivalent amount of privation and exertion. In this report are given the results of the study of the size of the heart only. Physical examinations were made and electrocardiograms were taken, but the results of these further studies are reserved for later communications.
The examinations now reported were roentgenographic.3 The exposures were made with sternum turned to, and parallel with, the plate. The distance