It is not an unusual occurrence at athletic contests to see a collapse during or at the end of a hard race. When he collapses the clinical picture is that of utter exhaustion, the patient gasping for air and yet being unable to take a full breath. He complains of abdominal pain and is more comfortable lying on his side doubled up, with both hands pressed tightly against the abdomen. The pulse is rapid and not of good quality. Although the patient is perspiring freely, his body feels cold. There is often considerable nausea and not uncommonly vomiting, and in extreme cases there may be unconsciousness. Various reasons have been given in explanation of the cause of this collapse. Rarely it has been brought about by rupture of a heart valve. Some medical observers have attributed it to an acute cardiac dilatation. The latter condition does not seem to fit